U.S. patent number 9,633,848 [Application Number 14/438,744] was granted by the patent office on 2017-04-25 for photosensitive resin composition, method for producing patterned cured film, semiconductor element and electronic device.
This patent grant is currently assigned to HITACHI CHEMICAL COMPANY, LTD.. The grantee listed for this patent is HITACHI CHEMICAL COMPANY, LTD.. Invention is credited to Yu Aoki, Kei Kasuya, Hiroshi Matsutani, Shigeru Nobe, Shingo Tahara, Akitoshi Tanimoto.
United States Patent |
9,633,848 |
Aoki , et al. |
April 25, 2017 |
Photosensitive resin composition, method for producing patterned
cured film, semiconductor element and electronic device
Abstract
Disclosed is a photosensitive resin composition comprising (A)
an alkali-soluble resin having a structural unit represented by the
following formula (1), (B) a compound that generates an acid by
light, (C) a thermal crosslinking agent, and (D) an acryl resin
having a structural unit represented by the following formula (2):
##STR00001## wherein R.sup.1 represents a hydrogen atom or a methyl
group; R.sup.2 represents an alkyl group having 1 to 10 carbon
atoms, or the like; and a represents an integer of 0 to 3, b
represents an integer of 1 to 3, and the total of a and b is 5 or
less, and ##STR00002## wherein R.sup.3 represents a hydrogen atom
or a methyl group; and R.sup.4 represents a hydroxyalkyl group
having 2 to 20 carbon atoms.
Inventors: |
Aoki; Yu (Hitachi,
JP), Nobe; Shigeru (Hitachi, JP),
Matsutani; Hiroshi (Tsukuba, JP), Kasuya; Kei
(Hitachi, JP), Tanimoto; Akitoshi (Hitachi,
JP), Tahara; Shingo (Hitachi, JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
HITACHI CHEMICAL COMPANY, LTD. |
Tokyo |
N/A |
JP |
|
|
Assignee: |
HITACHI CHEMICAL COMPANY, LTD.
(Tokyo, JP)
|
Family
ID: |
50627116 |
Appl.
No.: |
14/438,744 |
Filed: |
October 9, 2013 |
PCT
Filed: |
October 09, 2013 |
PCT No.: |
PCT/JP2013/077525 |
371(c)(1),(2),(4) Date: |
April 27, 2015 |
PCT
Pub. No.: |
WO2014/069202 |
PCT
Pub. Date: |
May 08, 2014 |
Prior Publication Data
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|
|
Document
Identifier |
Publication Date |
|
US 20150325431 A1 |
Nov 12, 2015 |
|
Foreign Application Priority Data
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|
|
|
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Oct 31, 2012 [JP] |
|
|
2012-240567 |
Dec 26, 2012 [JP] |
|
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2012-282958 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08F
212/22 (20200201); C08F 112/14 (20130101); G03F
7/0388 (20130101); C08F 12/22 (20130101); H01L
23/3114 (20130101); H01L 23/5329 (20130101); C08L
25/18 (20130101); G03F 7/40 (20130101); H01L
21/02118 (20130101); C08F 8/12 (20130101); C09D
125/18 (20130101); H01L 23/293 (20130101); C08F
212/14 (20130101); H01L 21/0274 (20130101); G03F
7/0233 (20130101); G03F 7/038 (20130101); C08F
212/14 (20130101); C08F 212/08 (20130101); C08F
8/12 (20130101); C08F 12/22 (20130101); C08L
25/18 (20130101); C08L 33/08 (20130101); C08F
8/12 (20130101); C08F 212/14 (20130101); C08F
8/12 (20130101); C08F 112/14 (20130101); C08F
212/22 (20200201); C08F 212/08 (20130101); H01L
2224/0401 (20130101); H01L 2224/05018 (20130101); H01L
2224/05124 (20130101); H01L 2224/05599 (20130101); H01L
2224/05008 (20130101); H01L 2224/73104 (20130101); H01L
2224/05099 (20130101); C08F 220/1804 (20200201); C08F
2800/10 (20130101); H01L 2224/2919 (20130101); H01L
2224/131 (20130101); H01L 2224/05022 (20130101); H01L
2224/02125 (20130101); H01L 2224/10126 (20130101); H01L
2224/05572 (20130101); H01L 24/13 (20130101); H01L
2224/13022 (20130101); H01L 2224/05572 (20130101); H01L
2924/00014 (20130101); H01L 2224/05599 (20130101); H01L
2924/00014 (20130101); H01L 2224/05099 (20130101); H01L
2924/00014 (20130101); H01L 2224/05124 (20130101); H01L
2924/00014 (20130101); H01L 2224/131 (20130101); H01L
2924/014 (20130101); H01L 2224/2919 (20130101); H01L
2924/00014 (20130101); C08F 220/1804 (20200201); C08F
220/06 (20130101); C08F 220/1812 (20200201); C08F
220/20 (20130101); C08F 226/06 (20130101); C08F
220/1804 (20200201); C08F 220/06 (20130101); C08F
220/1812 (20200201); C08F 220/20 (20130101); C08F
220/34 (20130101); C08F 220/1804 (20200201); C08F
220/06 (20130101); C08F 220/1812 (20200201); C08F
220/20 (20130101); C08F 226/06 (20130101); C08F
220/1804 (20200201); C08F 220/06 (20130101); C08F
220/1812 (20200201); C08F 220/20 (20130101); C08F
220/34 (20130101) |
Current International
Class: |
G03F
7/023 (20060101); C08F 12/22 (20060101); C08F
112/14 (20060101); C08L 25/18 (20060101); G03F
7/038 (20060101); G03F 7/40 (20060101); C09D
125/18 (20060101); C08F 8/12 (20060101); C08F
12/24 (20060101); C08F 220/34 (20060101); C08F
220/36 (20060101); H01L 51/00 (20060101); H01L
21/027 (20060101); H01L 21/02 (20060101); H01L
23/29 (20060101); H01L 23/31 (20060101); H01L
23/532 (20060101); C08F 212/14 (20060101); H01L
23/00 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
|
|
|
|
1482360 |
|
Dec 2004 |
|
EP |
|
2003233185 |
|
Aug 2003 |
|
JP |
|
2007057595 |
|
Mar 2007 |
|
JP |
|
2008309885 |
|
Dec 2008 |
|
JP |
|
2009047761 |
|
Mar 2009 |
|
JP |
|
2009244663 |
|
Mar 2009 |
|
JP |
|
2009024663 |
|
Oct 2009 |
|
JP |
|
2010073948 |
|
Apr 2010 |
|
JP |
|
200304583 |
|
Oct 2003 |
|
TW |
|
2007122929 |
|
Nov 2007 |
|
WO |
|
2008026406 |
|
Mar 2008 |
|
WO |
|
Other References
Decision to Grant a Patent mailed Dec. 9, 2014, for Japanese
Application No. 2014-544405, together with English language
translation thereof. cited by applicant .
International Search Report for International Application No.
PCT/JP2013/077525 dated May 14, 2015. cited by applicant .
International Search Report for International Application No.
PCT/JP2013/077525 dated Dec. 3, 2013. cited by applicant .
Supplementary European Search Report, mailed Sep. 20, 2016, for
European Application No. 13850182.0. cited by applicant .
Office Action mailed Jan. 23, 2017, in Taiwanese Application No.
102138359. cited by applicant.
|
Primary Examiner: Angerbranndt; Martin
Attorney, Agent or Firm: Fitch, Even, Tabin & Flannery,
LLP
Claims
The invention claimed is:
1. A photosensitive resin composition, comprising: (A) an
alkali-soluble resin having a structural unit represented by the
following formula (1): ##STR00028## wherein R.sup.1 represents a
hydrogen atom or a methyl group; R.sup.2 represents an alkyl group
having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon
atoms or an alkoxy group having 1 to 10 carbon atoms; and a
represents an integer of 0 to 3, b represents an integer of 1 to 3,
and a total of a and b is 5 or less; (B) a compound that generates
an acid by light; (C) a thermal crosslinking agent; and (D) an
acryl resin having a structural unit represented by the following
formula (2) and a structural unit represented by the following
formula (3): ##STR00029## wherein R.sup.3 represents a hydrogen
atom or a methyl group; and R.sup.4 represents a hydroxyalkyl group
having 2 to 20 carbon atoms; ##STR00030## wherein R.sup.5
represents a hydrogen atom or a methyl group; and R.sup.6
represents a monovalent organic group having a primary, secondary
or tertiary amino group wherein the photosensitive resin has a haze
value of less than 7%.
2. The photosensitive resin composition according to claim 1,
wherein the (D) component is the acryl resin further having a
structural unit represented by the following formula (4):
##STR00031## wherein R.sup.7 represents a hydrogen atom or a methyl
group; and R.sup.8 represents an alkyl group having 4 to 20 carbon
atoms.
3. The photosensitive resin composition according to claim 1,
wherein the (D) component is the acryl resin further having a
structural unit represented by the following formula (5):
##STR00032## wherein R.sup.9 represents a hydrogen atom or a methyl
group.
4. The photosensitive resin composition according to claim 1,
wherein the (A) component is the alkali-soluble resin further
having a structural unit represented by the following formula (6):
##STR00033## wherein R.sup.10 represents a hydrogen atom or a
methyl group; R.sup.11 represents an alkyl group having 1 to 10
carbon atoms, an aryl group having 6 to 10 carbon atoms or an
alkoxy group having 1 to 10 carbon atoms; and c represents an
integer of 0 to 3.
5. The photosensitive resin composition according to claim 1,
wherein the (A) component is the alkali-soluble resin further
having a structural unit represented by the following formula (7):
##STR00034## wherein R.sup.12 represents a hydrogen atom or a
methyl group; and R.sup.13 represents an alkyl group having 1 to 10
carbon atoms or a hydroxyalkyl group having 1 to 10 carbon
atoms.
6. The photosensitive resin composition according to claim 1,
wherein the (B) component is an o-quinone diazide compound.
7. The photosensitive resin composition according to claim 1,
wherein the (C) component comprises a thermal crosslinking agent
having an alkoxymethyl group; and the photosensitive resin
composition further comprises (E) a phenolic low molecular weight
compound.
8. The photosensitive resin composition according to claim 7,
wherein the (E) component is a phenolic low molecular weight
compound represented by the following formula (13), (14) or (15):
##STR00035## wherein R.sup.18 represents a hydrogen atom or a
methyl group; and a1 to f1 represent an integer of 0 to 3, a total
of d1 to f1 is 1 or more, a total of a1 and d1 is 5 or less, a
total of b1 and e1 is 5 or less, and a total of c1 and f1 is 5 or
less; ##STR00036## wherein R.sup.19 represents a hydrogen atom or a
methyl group; and a2 to c2 represent an integer of 0 to 3, d2 to f2
represent an integer of 1 to 3, a total of a2 and d2 is 5 or less,
a total of b2 and e2 is 5 or less, and a total of c2 and f2 is 5 or
less; or ##STR00037## wherein a3, c3, h and i represent an integer
of 0 to 3, d3 and f3 represent an integer of 1 to 3, a total of a3
and d3 is 5 or less, a total of c3 and f3 is 5 or less, and a total
of h and i is 4 or less.
9. A patterned cured film, being obtained by heating the
photosensitive resin composition according to claim 1.
10. A method for producing a patterned cured film, comprising: a
step of applying and drying the photosensitive resin composition
according to claim 1 on a part or the whole of a substrate to
thereby form a resin film; a step of exposing a part or the whole
of the resin film; a step of developing the resin film after the
exposure with an alkali aqueous solution to thereby form a
patterned resin film; and a step of heating the patterned resin
film.
11. A semiconductor element, having a patterned cured film formed
by the method for producing a patterned cured film according to
claim 10, as an interlayer insulating layer.
12. A semiconductor element, having a patterned cured film formed
by the method for producing a patterned cured film according to
claim 10, as a surface protecting layer.
13. An electronic device, comprising the semiconductor element
according to claim 11.
14. A photosensitive resin composition, comprising: (A) an
alkali-soluble resin having a structural unit represented by the
following formula (1): ##STR00038## wherein R.sup.1 represents a
hydrogen atom or a methyl group; R.sup.2 represents an alkyl group
having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon
atoms or an alkoxy group having 1 to 10 carbon atoms; and a
represents an integer of 0 to 3, b represents an integer of 1 to 3,
and a total of a and b is 5 or less; (B) a compound that generates
an acid by light; (C) a thermal crosslinking agent; and (D) an
acryl resin having a structural unit represented by the following
formula (2) and a structural unit represented by the following
formula (4): ##STR00039## wherein R.sup.3 represents a hydrogen
atom or a methyl group; and R.sup.4 represents a hydroxyalkyl group
having 2 to 20 carbon atoms; ##STR00040## wherein R.sup.7
represents a hydrogen atom or a methyl group; and R.sup.8
represents an alkyl group having 4 to 20 carbon atoms wherein the
photosensitive resin has a haze value of less than 7%.
15. The photosensitive resin composition according to claim 14,
wherein the (D) component is the acryl resin further having a
structural unit represented by the following formula (5):
##STR00041## wherein R.sup.9 represents a hydrogen atom or a methyl
group.
16. The photosensitive resin composition according to claim 14,
wherein the (A) component is the alkali-soluble resin further
having a structural unit represented by the following formula (6):
##STR00042## wherein R.sup.10 represents a hydrogen atom or a
methyl group; R.sup.11 represents an alkyl group having 1 to 10
carbon atoms, an aryl group having 6 to 10 carbon atoms or an
alkoxy group having 1 to 10 carbon atoms; and c represents an
integer of 0 to 3.
17. The photosensitive resin composition according to claim 14,
wherein the (A) component is the alkali-soluble resin further
having a structural unit represented by the following formula (7):
##STR00043## wherein R.sup.12 represents a hydrogen atom or a
methyl group; and R.sup.13 represents an alkyl group having 1 to 10
carbon atoms or a hydroxyalkyl group having 1 to 10 carbon
atoms.
18. The photosensitive resin composition according to claim 14,
wherein the (B) component is an o-quinone diazide compound.
19. The photosensitive resin composition according to claim 14,
wherein the (C) component comprises a thermal crosslinking agent
having an alkoxymethyl group; and the photosensitive resin
composition further comprises (E) a phenolic low molecular weight
compound.
20. The photosensitive resin composition according to claim 19,
wherein the (E) component is a phenolic low molecular weight
compound represented by the following formula (13), (14) or (15):
##STR00044## wherein R.sup.18 represents a hydrogen atom or a
methyl group; and a1 to f1 represent an integer of 0 to 3, a total
of d1 to f1 is 1 or more, a total of a1 and d1 is 5 or less, a
total of b1 and e1 is 5 or less, and a total of c1 and f1 is 5 or
less; ##STR00045## wherein R.sup.19 represents a hydrogen atom or a
methyl group; and a2 to c2 represent an integer of 0 to 3, d2 to f2
represent an integer of 1 to 3, a total of a2 and d2 is 5 or less,
a total of b2 and e2 is 5 or less, and a total of c2 and f2 is 5 or
less; or ##STR00046## wherein a3, c3, h and i represent an integer
of 0 to 3, d3 and f3 represent an integer of 1 to 3, a total of a3
and d3 is 5 or less, a total of c3 and f3 is 5 or less, and a total
of h and i is 4 or less.
Description
TECHNICAL FIELD
The present invention relates to a photosensitive resin
composition, a method for producing a patterned cured film, a
semiconductor element, and an electronic device.
BACKGROUND ART
In recent years, it has been demanded with high integration and
miniaturization of semiconductor elements that surface protecting
layers and interlayer insulating layers of the semiconductor
elements have better electric properties (dielectric constant and
the like), heat resistances (thermal expansion coefficient, glass
transition temperature and the like), mechanical properties
(elastic modulus, elongation at break, and the like), and the like.
As materials to form surface protecting layers and interlayer
insulating layers simultaneously having such properties,
photosensitive resin compositions containing an alkali-soluble
resin having a phenolic hydroxyl group are developed (see, for
example, Patent Literatures 1, 2 and 3). These photosensitive resin
compositions are applied and dried on substrates to thereby form
resin films, and the resin films are exposed and developed to
thereby obtain patterned resin films (resin films where patterns
are formed). Then, the patterned resin films are thermally cured to
be thereby able to form patterned cured films (cured films where
patterns are formed), and the patterned cured films can be used as
surface protecting layers and interlayer insulating layers.
Further, these photosensitive resin compositions have an advantage
of being capable of being thermally cured at a low temperature in a
step of forming patterned cured films.
CITATION LIST
Patent Literature
Patent Literature 1: JP2008-309885A Patent Literature 2:
JP2007-57595A Patent Literature 3: WO2010/073948
SUMMARY OF INVENTION
Technical Problem
Then, in a photosensitive resin composition, in the case where the
compatibility of each component such as a resin and a
photosensitizer is poor, the photosensitive resin composition
becomes cloudy, and further a patterned cured film formed on a
substrate is likely to become cloudy. When a patterned cured film
becomes cloudy, in a producing step of a semiconductor element
after the patterned cured film is formed, marks for alignment made
on a substrate are hardly recognized and the work becomes
difficult.
A patterned cured film formed from a photosensitive resin
composition, when a semiconductor element is formed and the formed
semiconductor element is mounted on a wiring board, is exposed to
various high-temperature conditions and low-temperature conditions.
Therefore, it is demanded not only that mechanical properties are
excellent, but also that the changing rates of the mechanical
properties after being left at a high temperature and after a
thermal shock test are low. When the changing rates of the
mechanical properties after being left at a high temperature and
after a thermal shock test are high, there arises a problem of
generating cracks in a patterned cured film.
However, it is difficult that conventional photosensitive resin
compositions satisfy all of such properties that the white
turbidity can sufficiently be suppressed; the mechanical properties
of a formed patterned cured film are excellent; and the changing
rates of the mechanical properties after being left at a high
temperature and after a thermal shock test are low.
Then, the present invention has an object to provide a
photosensitive resin composition in which white turbidity can
sufficiently be suppressed; mechanical properties of a formed
patterned cured film are excellent; and the changing rates of
mechanical properties after being left at a high temperature and
after a thermal shock test are low. The present invention has also
an object to provide a method for producing a patterned cured film
using the photosensitive resin composition, a semiconductor element
having the patterned cured film as an interlayer insulating layer
or a surface protecting layer, and an electronic device having the
semiconductor element.
Solution to Problem
The present invention relates to the following.
<1> A photosensitive resin composition, comprising:
(A) an alkali-soluble resin having a structural unit represented by
the following formula (1):
##STR00003## wherein R.sup.1 represents a hydrogen atom or a methyl
group; R.sup.2 represents an alkyl group having 1 to 10 carbon
atoms, an aryl group having 6 to 10 carbon atoms or an alkoxy group
having 1 to 10 carbon atoms; and a represents an integer of 0 to 3,
b represents an integer of 1 to 3, and the total of a and b is 5 or
less;
(B) a compound that generates an acid by light;
(C) a thermal crosslinking agent; and
(D) an acryl resin having a structural unit represented by the
following formula (2):
##STR00004## wherein R.sup.3 represents a hydrogen atom or a methyl
group; and R.sup.4 represents a hydroxyalkyl group having 2 to 20
carbon atoms. <2> The photosensitive resin composition
according to <1>, wherein the (D) component is the acryl
resin further having a structural unit represented by the following
formula (3):
##STR00005## wherein R.sup.5 represents a hydrogen atom or a methyl
group; and R.sup.6 represents a monovalent organic group having a
primary, secondary or tertiary amino group. <3> The
photosensitive resin composition according to <1> or
<2>, wherein the (D) component is the acryl resin further
having a structural unit represented by the following formula
(4):
##STR00006## wherein R.sup.7 represents a hydrogen atom or a methyl
group; and R.sup.8 represents an alkyl group having 4 to 20 carbon
atoms. <4> The photosensitive resin composition according to
any one of <1> to <3>, wherein the (D) component is the
acryl resin further having a structural unit represented by the
following formula (5):
##STR00007## wherein R.sup.9 represents a hydrogen atom or a methyl
group. <5> The photosensitive resin composition according to
any one of <1> to <4>, wherein the (A) component is the
alkali-soluble resin further having a structural unit represented
by the following formula (6):
##STR00008## wherein R.sup.10 represents a hydrogen atom or a
methyl group; R.sup.11 represents an alkyl group having 1 to 10
carbon atoms, an aryl group having 6 to 10 carbon atoms or an
alkoxy group having 1 to 10 carbon atoms; and c represents an
integer of 0 to 3. <6> The photosensitive resin composition
according to any one of <1> to <5>, wherein the (A)
component is the alkali-soluble resin further having a structural
unit represented by the following formula (7):
##STR00009## wherein R.sup.12 represents a hydrogen atom or a
methyl group; and R.sup.13 represents an alkyl group having 1 to 10
carbon atoms or a hydroxyalkyl group having 1 to 10 carbon atoms.
<7> The photosensitive resin composition according to any one
of <1> to <6>, wherein the (B) component is an
o-quinone diazide compound.
Then, in a photosensitive resin composition, since when the
solubility is made high, also the solubility of unexposed portions
is improved, there sometimes arises such a problem that the
remaining film ratio after the development decreases. By contrast,
when the solubility is decreased, there sometimes arise such a
problem that an undissolved residue is produced in patterned
openings, leading to a decrease in the resolution and a connection
failure in metal wiring formation, such a problem that since a high
exposure amount is needed, the workability decreases, and other
problems.
Therefore, in a photosensitive resin composition, the higher the
dissolution contrast between exposed portions and unexposed
portions, the more the above-mentioned problems can be suppressed.
By making a photosensitive resin composition according to the
present embodiment to have constitutions of <8> and
<9>, the photosensitive resin composition having an excellent
dissolution contrast between exposed portions and unexposed
portions can be provided.
<8> The photosensitive resin composition according to any one
of <1> to <7>, wherein the (C) component comprises a
thermal crosslinking agent having an alkoxymethyl group; and the
photosensitive resin composition further comprises (E) a phenolic
low molecular weight compound. <9> The photosensitive resin
composition according to <8>, wherein the (E) component is a
phenolic low molecular weight compound represented by the following
formula (13), (14) or (15):
##STR00010## wherein R.sup.18 represents a hydrogen atom or a
methyl group; and a1 to f1 represent an integer of 0 to 3, the
total of d1 to f1 is 1 or more, the total of a1 and d1 is 5 or
less, the total of b1 and e1 is 5 or less, and the total of c1 and
f1 is 5 or less;
##STR00011## wherein R.sup.19 represents a hydrogen atom or a
methyl group; and a2 to c2 represent an integer of 0 to 3, d2 to f2
represent an integer of 1 to 3, the total of a2 and d2 is 5 or
less, the total of b2 and e2 is 5 or less, and the total of c2 and
f2 is 5 or less; or
##STR00012## wherein a3, c3, h and i represent an integer of 0 to
3, d3 and f3 represent an integer of 1 to 3, the total of a3 and d3
is 5 or less, the total of c3 and f3 is 5 or less, and the total of
h and i is 4 or less. <10> A patterned cured film, being
obtained by heating the photosensitive resin composition according
to any one of <1> to <9>. <11> A method for
producing a patterned cured film, comprising: a step of applying
and drying the photosensitive resin composition according to any
one of <1> to <9> on a part or the whole of a substrate
to thereby form a resin film, a step of exposing a part or the
whole of the resin film, a step of developing the resin film after
the exposure with an alkali aqueous solution to thereby form a
patterned resin film, and a step of heating the patterned resin
film. <12> A semiconductor element, having a patterned cured
film formed by the method for producing a patterned cured film
according to <11>, as an interlayer insulating layer.
<13> A semiconductor element, having a patterned cured film
formed by the method for producing a patterned cured film according
to <11>, as a surface protecting layer. <14> An
electronic device, comprising the semiconductor element according
to <12> or <13>.
Advantageous Effects of Invention
According to the present invention, a photosensitive resin
composition can be provided in which white turbidity can
sufficiently be suppressed; mechanical properties of a formed
patterned cured film are excellent; and the changing rates of the
mechanical properties after being left at a high temperature and
after a thermal shock test are low. There can further be provided a
method for producing a patterned cured film using the
photosensitive resin composition, a semiconductor element having
the patterned cured film as an interlayer insulating layer or a
surface protecting layer, and an electronic device having the
semiconductor element.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1a is a schematic perspective view and FIG. 1b is a schematic
end view illustrating one embodiment of a producing process of a
semiconductor element.
FIG. 2a is a schematic perspective view and FIG. 2b is a schematic
end view illustrating one embodiment of a producing process of the
semiconductor element.
FIG. 3a is a schematic perspective view and FIG. 3b is a schematic
end view illustrating one embodiment of a producing process of the
semiconductor element.
FIG. 4a is a schematic perspective view and FIG. 4b is a schematic
end view illustrating one embodiment of a producing process of the
semiconductor element.
FIG. 5a is a schematic perspective view and FIG. 5b is a schematic
end view illustrating one embodiment of a producing process of the
semiconductor element.
FIG. 6 is a schematic cross-sectional diagram showing one
embodiment of semiconductor element.
FIG. 7 is a schematic cross-sectional diagram showing one
embodiment of semiconductor element.
DESCRIPTION OF EMBODIMENTS
[Photosensitive Resin Composition]
The photosensitive resin composition according to the present
embodiment contains (A) an alkali-soluble resin, (B) a compound
that generates an acid by light, (C) a thermal crosslinking agent
and (D) an acryl resin.
First, each component which a photosensitive resin composition
contains will be described.
<(A) Component>
(A) component is an alkali-soluble resin (soluble to an alkali
aqueous solution). Here, one criterion that an (A) component in the
present invention is soluble to an alkali aqueous solution will be
described hereinafter. A resin solution obtained from the (A)
component singly and an optional solvent, or a resin solution
obtained from the (A) component, and a (B) component, a (C)
component and a (D) component, which will be described in due order
hereinafter, is spin coated on a substrate such as a silicon wafer
to thereby form a resin film of about 5 .mu.m in film thickness.
The resin film is immersed in any one of a tetramethylammonium
hydroxide aqueous solution, a metal hydroxide aqueous solution and
an organic amine aqueous solution at 20 to 25.degree. C. As a
result, when the resin film is capable of being dissolved as a
homogeneous solution, such a judgment is made that the used (A)
component is soluble to the alkali aqueous solution.
An alkali-soluble resin as an (A) component has a structural unit
represented by the following formula (1):
##STR00013## wherein R.sup.1 represents a hydrogen atom or a methyl
group; R.sup.2 represents an alkyl group having 1 to 10 carbon
atoms, an aryl group having 6 to 10 carbon atoms or an alkoxy group
having 1 to 10 carbon atoms; and a represents an integer of 0 to 3,
b represents an integer of 1 to 3, and the total of a and b is 5 or
less.
(A) an alkali-soluble resin is obtained by polymerizing a monomer
and the like imparting a structural unit represented by the formula
(1).
Examples of alkyl groups having 1 to 10 carbon atoms represented by
R.sup.2 in the formula (1) include a methyl group, an ethyl group,
a propyl group, a butyl group, a pentyl group, a hexyl group, a
heptyl group, an octyl group, a nonyl group, and a decyl group.
These groups may be a straight chain one or a branched chain one.
Examples of aryl groups having 6 to 10 carbon atoms include a
phenyl group and a naphthyl group. Examples of alkoxy groups having
1 to 10 carbon atoms include a methoxy group, an ethoxy group, a
propoxy group, a butoxy group, a pentoxy group, a hexoxy group, a
heptoxy group, an octoxy group, a nonoxy group, and a decoxy group.
These groups may be a straight chain one or a branched chain
one.
Examples of monomers imparting a structural unit represented by the
formula (1) include p-hydroxystyrene, m-hydroxystyrene,
o-hydroxystyrene, p-isopropenylphenol, m-isopropenylphenol, and
o-isopropenylphenol. These monomers can be used singly or in a
combination of two or more.
A method of obtaining (A) an alkali-soluble resin is not especially
limited, but it can be obtained, for example, by protecting a
hydroxyl group of a monomer imparting a structural unit represented
by the formula (1) with a t-butyl group, an acetyl group or the
like to thereby make a monomer whose hydroxyl group is protected,
polymerizing the monomer whose hydroxyl group is protected to
thereby obtain a polymer, and further deprotecting the obtained
polymer by a well-known method (the deprotection is carried out,
for example, in the presence of an acid catalyst to convert to a
hydroxystyrene-based structural unit).
An (A) component may be a polymer composed only of a monomer or a
copolymer imparting a structural unit represented by the formula
(1), or may be a copolymer of a monomer imparting a structural unit
represented by the formula (1) and other monomers. In the case
where an (A) component is a copolymer, from the viewpoint of the
solubility of exposed portions to an alkali developing solution, it
is preferable that the proportion of a structural unit represented
by the formula (1) in the copolymer is 10 to 100 mol % with respect
to 100 mol % of the (A) component; 20 to 97 mol % is more
preferable; 30 to 95 mol % is still more preferable; and 50 to 95
mol % is especially preferable.
From the viewpoint of more improving the dissolution inhibition of
unexposed portions to an alkali developing solution, it is
preferable that an (A) component is the alkali-soluble resin
further having a structural unit represented by the following
formula (6):
##STR00014## wherein R.sup.10 represents a hydrogen atom or a
methyl group; R.sup.11 represents an alkyl group having 1 to 10
carbon atoms, an aryl group having 6 to 10 carbon atoms or an
alkoxy group having 1 to 10 carbon atoms; and c represents an
integer of 0 to 3.
Examples of the alkyl group having 1 to 10 carbon atoms, the aryl
group having 6 to 10 carbon atoms or the alkoxy group having 1 to
10 carbon atoms represented by R.sup.11 can each be the same as in
R.sup.2.
An alkali-soluble resin having a structural unit represented by the
formula (6) can be obtained by using a monomer imparting the
structural unit represented by the formula (6). Examples of the
monomer imparting the structural unit represented by the formula
(6) include aromatic vinyl compounds such as styrene,
.alpha.-methylstyrene, o-methylstyrene, m-methylstyrene,
p-methylstyrene, o-methoxystyrene, m-methoxystyrene and
p-methoxystyrene. These monomers can be used singly or in a
combination of two or more.
In the case where an (A) component is an alkali-soluble resin
having a structural unit represented by the formula (6), from the
viewpoint of the dissolution inhibition of unexposed portions to an
alkali developing solution and the mechanical properties of a
patterned cured film, it is preferable that the proportion of the
structural unit represented by the formula (6) is 1 to 90 mol %
with respect to 100 mol % of the (A) component; 3 to 80 mol % is
more preferable; 5 to 70 mol % is still more preferable; and 5 to
50 mol % is especially preferable.
Further from the viewpoint of lowering the elastic modulus, it is
preferable that an (A) component is the alkali-soluble resin
further having a structural unit represented by the following
formula (7):
##STR00015## wherein R.sup.12 represents a hydrogen atom or a
methyl group; and R.sup.13 represents an alkyl group having 1 to 10
carbon atoms or a hydroxyalkyl group having 1 to 10 carbon
atoms.
An alkali-soluble resin having a structural unit represented by the
formula (7) can be obtained by using a monomer imparting the
structural unit represented by the formula (7). Examples of the
monomer imparting the structural unit represented by the formula
(7) include methyl(meth)acrylate, ethyl(meth)acrylate,
propyl(meth)acrylate, butyl(meth)acrylate, pentyl(meth)acrylate,
hexyl(meth)acrylate, heptyl(meth)acrylate, octyl(meth)acrylate,
nonyl(meth)acrylate, decyl(meth)acrylate,
hydroxymethyl(meth)acrylate, hydroxyethyl(meth)acrylate,
hydroxypropyl(meth)acrylate, hydroxybutyl(meth)acrylate,
hydroxypentyl(meth)acrylate, hydroxyhexyl(meth)acrylate,
hydroxyheptyl(meth)acrylate, hydroxyoctyl(meth)acrylate,
hydroxynonyl(meth)acrylate, and hydroxydecyl(meth)acrylate. These
monomers can be used singly or in a combination of two or more.
In the case where an (A) component is an alkali-soluble resin
having a structural unit represented by the formula (7), from the
viewpoint of the dissolution inhibition of unexposed portions to an
alkali developing solution and the mechanical properties of a
patterned cured film, it is preferable that the proportion of the
structural unit represented by the formula (7) is 1 to 90 mol %
with respect to 100 mol % of the (A) component; 3 to 80 mol % is
more preferable; 5 to 70 mol % is still more preferable; and 5 to
50 mol % is especially preferable.
From the viewpoint of the dissolution inhibition of unexposed
portions to an alkali developing solution and the mechanical
properties of a patterned cured film, it is preferable that an (A)
component is an alkali-soluble resin having a structural unit
represented by the formula (1) and a structural unit represented by
the formula (6), an alkali-soluble resin having a structural unit
represented by the formula (1) and a structural unit represented by
the formula (7), or an alkali-soluble resin having a structural
unit represented by the formula (1), a structural unit represented
by the formula (6) and a structural unit represented by the formula
(7). From the viewpoint of more developing the advantage of the
present invention, it is more preferable that an (A) component is
an alkali-soluble resin having a structural unit represented by the
formula (1) and a structural unit represented by the formula (6) or
(7).
In consideration of the balance among the solubility to an alkali
aqueous solution, the photosensitive properties and the mechanical
properties of a patterned cured film, it is preferable that the
molecular weight of an (A) component is 1000 to 500000 in
weight-average molecular weight; 2000 to 200000 is more preferable;
and 2000 to 100000 is still more preferable. Here, the
weight-average molecular weight is a value obtained by the
measurement using gel permeation chromatography (GPC), and the
conversion using a standard polystyrene calibration curve.
<(B) Component>
A compound that generates an acid by light (when exposed to light)
as a (B) component functions as a photosensitizer in a
photosensitive resin composition. The (B) component generates an
acid when exposed to light irradiation, and has a function of
increasing the solubility of light-irradiated portions to an alkali
aqueous solution. As the (B) component, a compound generally called
a photoacid generating agent can be used. Specific examples of the
(B) component include o-quinone diazide compounds, aryldiazonium
salts, diaryliodonium salts and triarylsulfonium salts. A (B)
component may be composed of only one of these compounds, or may be
constituted by containing two or more thereof. Among these,
o-quinone diazide compounds are preferable because being highly
sensitive.
As an o-quinone diazide compound, there can be used, for example,
one obtained by condensation reacting o-quinone diazidesulfonyl
chloride and a hydroxyl compound and/or an amino compound and the
like in the presence of a dehydrochlorinating agent.
Examples of o-quinone diazidesulfonyl chloride used in the reaction
include benzoquinone-1,2-diazide-4-sulfonyl chloride,
naphthoquinone-1,2-diazide-5-sulfonyl chloride, and
naphthoquinone-1,2-diazide-6-sulfonyl chloride.
Examples of the hydroxyl compound used in the reaction include
hydroquinone, resorcinol, pyrogallol, bisphenol A,
bis(4-hydroxyphenyl)methane,
1,1-bis(4-hydroxyphenyl)-1-[4-{1-(4-hydroxyphenyl)-1-methylethyl}phenyl]e-
thane, 2,2-bis(4-hydroxyphenyl)hexafluoropropane,
2,3,4-trihydroxybenzophenone, 2,3,4,4'-tetrahydroxybenzophenone,
2,2',4,4'-tetrahydroxybenzophenone,
2,3,4,2',3'-pentahydroxybenzophenone,
2,3,4,3',4',5'-hexahydroxybenzophenone,
bis(2,3,4-trihydroxyphenyl)methane,
bis(2,3,4-trihydroxyphenyl)propane,
4b,5,9b,10-tetrahydro-1,3,6,8-tetrahydroxy-5,10-dimethylindeno[2,1-a]inde-
ne, tris(4-hydroxyphenyl)methane, and
tris(4-hydroxyphenyl)ethane.
Examples of the amino compound used in the reaction include
p-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenyl ether,
4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone,
4,4'-diaminodiphenylsulfide, o-aminophenol, m-aminophenol,
p-aminophenol, 3,3'-diamino-4,4'-dihydroxybiphenyl,
4,4'-diamino-3,3'-dihydroxybiphenyl,
bis(3-amino-4-hydroxyphenyl)propane,
bis(4-amino-3-hydroxyphenyl)propane,
bis(3-amino-4-hydroxyphenyl)sulfone,
bis(4-amino-3-hydroxyphenyl)sulfone,
bis(3-amino-4-hydroxyphenyl)hexafluoropropane, and
bis(4-amino-3-hydroxyphenyl)hexafluoropropane.
Among these, it is preferable from the viewpoint of the reactivity
when an o-quinone diazide compound is synthesized and the viewpoint
of a proper absorption wavelength range when a resin film is
exposed, that there is used an o-quinone diazide compound obtained
by condensation reacting
1,1-bis(4-hydroxyphenyl)-1-[4-{1-(4-hydroxyphenyl)-1-methylethyl-
}phenyl]ethane and 1-naphtoquinone-2-diazide-5-sulfonyl chloride,
or one obtained by condensation reacting
tris(4-hydroxyphenyl)methane or tris(4-hydroxyphenyl)ethane and
1-naphtoquinone-2-diazide-5-sulfonyl chloride.
Examples of the dehydrochlorinating agent used in the reaction
include sodium carbonate, sodium hydroxide, sodium
hydrogenecarbonate, potassium carbonate, potassium hydroxide,
trimethylamine, triethylamine, and pyridine. As the reaction
solvent, for example, dioxane, acetone, methyl ethyl ketone,
tetrahydrofuran, diethyl ether, and N-methylpyrrolidone are
used.
It is preferable that o-quinone diazidesulfonyl chloride and a
hydroxyl compound and/or an amino compound are blended so that the
total of the numbers of moles of a hydroxyl group and an amino
group is 0.5 to 1 mol with respect to 1 mol of o-quinone
diazidesulfonyl chloride. The preferable blend proportion of the
dehydrochlorinating agent to o-quinone diazidesulfonyl chloride is
in the range of 0.95/1 mol to 1/0.95 mol equivalent.
The preferable reaction temperature for the above-mentioned
reaction is 0 to 40.degree. C., and the preferable reaction time is
1 to 10 hours.
It is preferable that the content of a (B) component is 3 to 100
parts by mass with respect to 100 parts by mass of an (A)
component; 5 to 50 parts by mass is more preferable; 5 to 30 parts
by mass is still more preferable; and 5 to 20 parts by mass is
especially preferable, because the dissolving speed difference
between exposed portions and unexposed portions becomes large,
making the sensitivity better.
<(C) Component>
A thermal crosslinking agent as a (C) component is a compound
having a structure capable of reacting with an (A) component and
forming a crosslinked structure when a patterned resin film is
heated and cured. This can prevent the brittleness of a film and
the melt of the film. Examples of the (C) component include
compounds having a phenolic hydroxyl group, compounds having an
alkoxymethylamino group and compounds having an epoxy group.
A "compound having a phenolic hydroxyl group" mentioned herein does
not include (A) the alkali-soluble resin and (E) the phenolic low
molecular weight compound. The compound having a phenolic hydroxyl
group as a thermal crosslinking agent not only serves as a thermal
crosslinking agent but also can increase the dissolution speed of
exposed portions in the development with an alkali aqueous solution
and improve the sensitivity. In consideration of the balance among
the solubility to an alkali aqueous solution, the photosensitive
properties and the mechanical properties, it is preferable that the
weight-average molecular weight of such a compound having a
phenolic hydroxyl group is 2000 or lower; 94 to 2000 is more
preferable; 108 to 2000 is still more preferable; and 108 to 1500
is especially preferable.
As the compound having a phenolic hydroxyl group, conventionally
well-known ones can be used, but a compound having an alkoxymethyl
group and a phenolic hydroxyl group is preferable; and a compound
represented by the following formula (8) is more preferable,
because of being excellent in the balance between the effect of
promoting the dissolution of exposed portions and the effect of
preventing the melt of a photosensitive resin film in curing.
##STR00016## wherein X represents a single bond or a divalent
organic group; R.sup.14, R.sup.15, R.sup.16 and R.sup.17 each
independently represent a hydrogen atom or a monovalent organic
group; and s and t each independently represent an integer of 1 to
3, and u and v each independently represent an integer of 0 to
3.
In the formula (8), compounds in which X is a single bond are
biphenol (dihydroxybiphenyl) derivatives. Examples of divalent
organic groups represented by X include alkylene groups having 1 to
10 carbon atoms such as a methylene group, an ethylene group and a
propylene group, alkylidene groups having 2 to 10 carbon atoms such
as an ethylidene group, arylene groups having 6 to 30 carbon atoms
such as a phenylene group, groups in which a part or the whole of a
hydrogen atom of these hydrocarbon groups is substituted with a
halogen atom such as a fluorine atom, a sulfonyl group, a carbonyl
group, an ether bond, a thioether bond, and an amide bond. Further,
examples of the monovalent organic groups represented by R.sup.14,
R.sup.15, R.sup.16 and R.sup.17 include alkyl groups having 1 to 10
carbon atoms such as a methyl group, an ethyl group and a propyl
group, alkenyl groups having 2 to 10 carbon atoms such as a vinyl
group, aryl groups having 6 to 30 carbon atoms such as a phenyl
group, and groups in which a part or the whole of these hydrocarbon
groups is substituted with a halogen atom such as a fluorine
atom.
As a compound represented by the above formula (8), there can be
used, for example, 1,1-bis
{3,5-bis(methoxymethyl)-4-hydroxyphenyl}methane (made by Honshu
Chemical Industry Co., Ltd., trade name: "TMOM-pp-BPF").
Examples of a compound having an alkoxymethylamino group include
nitrogen-containing compounds in which the whole or a part of an
active methylol group of (poly)(N-hydroxymethyl)melamine,
(poly)(N-hydroxymethyl)glycoluril,
(poly)(N-hydroxymethyl)benzoguanamine, and (poly)(N-hydroxymethyl)
urea or the like is alkyl-etherified. Here, examples of alkyl
groups in the alkyl ethers include a methyl group, an ethyl group,
and a butyl group, and oligomer components partially self-condensed
may be contained. Specific examples of a compound having an
alkoxymethylamino group include hexakis(methoxymethyl)melamine,
hexakis(butoxymethyl)melamine, tetrakis(methoxymethyl)glycoluril,
tetrakis(butoxymethyl)glycoluril, and
tetrakis(methoxymethyl)urea.
As the compound having an epoxy group, conventionally well-known
ones can be used. Specific examples thereof include bisphenol A
epoxy resins, bisphenol F epoxy resins, phenol novolac-type epoxy
resins, cresol novolac-type epoxy resins, alicyclic epoxy resins,
glycidylamines, heterocyclic epoxy resins, and polyalkylene glycol
diglycidyl ethers.
As the (C) component, other than the above-mentioned compounds,
there can also be used, for example, aromatic compounds having a
hydroxymethyl group such as bis[3,4-bis(hydroxymethyl)phenyl]ether,
1,3,5-tris(1-hydroxy-1-methylethyl)benzene or the like, compounds
having a maleimide group such as bis(4-maleimidephenyl)methane,
2,2-bis[(4-(4'-maleimidephenoxy)phenyl)]propane or the like,
compounds having a norbornene skeleton, polyfunctional acrylate
compounds, compounds having an oxetanyl group, compounds having a
vinyl group, and blocked isocyanate compounds.
Among the above-mentioned (C) components, compounds having an
alkoxymethyl group and a phenolic hydroxyl group or compounds
having an alkoxymethylamino group are preferably used from the
viewpoint of being capable of more improving the sensitivity and
the heat resistance; and from the viewpoint of being capable of
more improving the resolution and the elongation of a coated film
as well, compounds having an alkoxymethylamino group are more
preferable; compounds having an alkoxymethylamino group in which
the whole or a part of hydroxymethylamino groups is
alkyl-etherified are still more preferable; and compounds having an
alkoxymethylamino group in which the whole of hydroxymethylamino
groups is alkyl-etherified are especially preferable.
Among the compounds having an alkoxymethylamino group in which the
whole of hydroxymethylamino groups is alkyl-etherified, a compound
represented by the following formula (9) is preferable.
##STR00017## wherein R.sup.31 to R.sup.36 each independently
represent an alkyl group having 1 to 10 carbon atoms.
Examples of alkyl groups having 1 to 10 carbon atoms represented by
R.sup.31 to R.sup.36 in the formula (9) include a methyl group, an
ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl
group, a heptyl group, an octyl group, a nonyl group and a decyl
group. These groups may be a straight chain one or a branched chain
one.
From the viewpoint that the dissolution speed difference between
exposed portions and unexposed portions becomes large and the
sensitivity becomes good, it is preferable that the content of a
(C) component is 0.5 to 50 parts by mass with respect to 100 parts
by mass of an (A) component; 1 to 40 parts by mass is more
preferable; and 2 to 30 parts by mass is still more preferable.
<(D) Component>
An acryl resin as the (D) component has a structural unit
represented by the following formula (2).
##STR00018## wherein R.sup.3 represents a hydrogen atom or a methyl
group; and R.sup.4 represents a hydroxyalkyl group having 2 to 20
carbon atoms.
In a photosensitive resin composition according to the present
embodiment, the white turbidity of the photosensitive resin
composition can sufficiently be suppressed and the haze value of a
patterned cured film can be made low by the incorporation of a (D)
component having a structural unit represented by the formula (2).
Further by the incorporation of a (D) component, the photosensitive
properties and the heat shock properties (the changing rates of
mechanical properties after being left at a high temperature and
after a thermal shock test are low) can be improved more. The (D)
component may be composed only of one acryl resin or may contain
two or more acryl resins.
Since the interaction of a (D) component and an (A) component
becomes good and the compatibility thereof is improved by the
incorporation of a structural unit represented by the formula (2)
in the (D) component, the adherence to a substrate, the mechanical
properties and the heat shock properties of resist patterns can be
improved more.
From the viewpoint of being able to more improve the compatibility
with an (A) component and the heat shock properties, it is
preferable that R.sup.4 in the formula (2) is a hydroxyalkyl group
having 2 to 15 carbon atoms; a hydroxyalkyl group having 2 to 10
carbon atoms is more preferable; and a hydroxyalkyl group having 2
to 8 carbon atoms is especially preferable.
Examples of hydroxyalkyl groups having 2 to 20 carbon atoms
represented by R.sup.4 include a hydroxyethyl group, a
hydroxypropyl group, a hydroxybutyl group, a hydroxypentyl group, a
hydroxyhexyl group, a hydroxyheptyl group, a hydroxyoctyl group, a
hydroxynonyl group, a hydroxydecyl group, a hydroxyundecyl group, a
hydroxydodecyl group (it may be called a hydroxylauryl group), a
hydroxytridecyl group, a hydroxytetradecyl group, a
hydroxypentadecyl group, a hydroxyhexadecyl group, a
hydroxyheptadecyl group, a hydroxyoctadecyl group, a
hydroxynonadecyl group, and a hydroxyeicosyl group. These groups
may be a straight chain one or a branched chain one.
Examples of monomers making an acryl resin having a structural unit
represented by the formula (2) include hydroxyalkyl(meth)acrylates.
An example of such a hydroxyalkyl(meth)acrylate includes a compound
represented by the following formula (10):
CH.sub.2.dbd.C(R.sup.3)--COOR.sup.4 (10) wherein R.sup.3 represents
a hydrogen atom or a methyl group; and R.sup.4 represents a
hydroxyalkyl group having 2 to 20 carbon atoms.
From the viewpoint of being able to more highly develop the
advantage of the present invention, it is desirable that an acryl
resin having a structural unit represented by the formula (2) is
added as a polymer.
Examples of monomers represented by the formula (10) include
hydroxyethyl(meth)acrylate, hydroxypropyl(meth)acrylate,
hydroxybutyl(meth)acrylate, hydroxypentyl(meth)acrylate,
hydroxyhexyl(meth)acrylate, hydroxyheptyl(meth)acrylate,
hydroxyoctyl(meth)acrylate, hydroxynonyl(meth)acrylate,
hydroxydecyl(meth)acrylate, hydroxyundecyl(meth)acrylate,
hydroxydodecyl(meth)acrylate (it may be called
hydroxylauryl(meth)acrylate), hydroxytridecyl(meth)acrylate,
hydroxytetradecyl(meth)acrylate, hydroxypentadecyl(meth)acrylate,
hydroxyhexadecyl(meth)acrylate, hydroxyheptadecyl(meth)acrylate,
hydroxyoctadecyl(meth)acrylate, hydroxynonadecyl(meth)acrylate, and
hydroxyeicosyl(meth)acrylate. These monomers are used singly or in
a combination of two or more. Among these, from the viewpoint of
more improving the compatibility with an (A) component and the
elongation at break, it is preferable that there is used
hydroxyethyl(meth)acrylate, hydroxypropyl(meth)acrylate,
hydroxybutyl(meth)acrylate, hydroxypentyl(meth)acrylate,
hydroxyhexyl(meth)acrylate, hydroxyheptyl(meth)acrylate,
hydroxyoctyl(meth)acrylate, hydroxynonyl(meth)acrylate,
hydroxydecyl(meth)acrylate, hydroxyundecyl(meth)acrylate, or
hydroxydodecyl(meth)acrylate.
A (D) component may be an acryl resin composed only of a structural
unit represented by the formula (2) or may be an acryl resin having
a structural unit other than the structural unit represented by the
formula (2). In the case of an acryl resin having a structural unit
other than the structural unit represented by the formula (2), it
is preferable that the proportion of the structural unit
represented by the formula (2) in the acryl resin is 0.1 to 30 mol
% with respect to the total amount of the (D) component; 0.3 to 20
mol % is more preferable; and 0.5 to 10 mol % is still more
preferable. When the compositional ratio of a structural unit
represented by the above formula (2) is 0.1 to 30 mol %, the
compatibility with an (A) component and the heat shock properties
of a patterned cured film can be improved more.
It is preferable that a (D) component is the acryl resin further
having a structural unit represented by the following formula
(3):
##STR00019## wherein R.sup.5 represents a hydrogen atom or a methyl
group; and R.sup.6 represents a monovalent organic group having a
primary, secondary or tertiary amino group.
When a (D) component has a structural unit represented by the
formula (3), the dissolution inhibition of unexposed portions to a
developing solution can be improved more.
Examples of a monomer imparting an acryl resin having a structural
unit represented by the formula (3) include
aminoethyl(meta)acrylate, N-methylaminoethyl(meta)acrylate,
N,N-dimethylaminoethyl(meta)acrylate,
N-ethylaminoethyl(meta)acrylate, N,N-diethylamino
ethyl(meta)acrylate, aminopropyl(meta)acrylate,
N-methylaminopropyl(meta)acrylate,
N,N-dimethylaminopropyl(meta)acrylate,
N-ethylaminopropyl(meta)acrylate,
N,N-diethylaminopropyl(meta)acrylate, piperidin-4-yl(meta)acrylate,
1-methylpiperidin-4-yl(meta)acrylate,
2,2,6,6-tetramethylpiperidin-4-yl(meta)acrylate,
1,2,2,6,6-pentamethylpiperidin-4-yl(meta)acrylate,
(piperidin-4-yl)methyl(meta)acrylate, and
2-(piperidin-4-yl)ethyl(meta)acrylate. These monomers are used
singly or in a combination of two or more. Among these, from the
viewpoint of more improving the adherence to a substrate, the
mechanical properties and the heat shock properties of a patterned
cured film, it is preferable that R.sup.6 in the formula (3) is a
monovalent organic group represented by the following formula
(11):
##STR00020## wherein Y represents an alkylene group having 1 to 5
carbon atoms; R.sup.21 to R.sup.25 each independently represent a
hydrogen atom or an alkyl group having 1 to 20 carbon atoms; and n
represents an integer of 0 to 10.
In the formula (3), examples of a polymerizable monomer imparting a
structural unit whose R.sup.6 is represented by a monovalent
organic group represented by the formula (11) include
piperidin-4-yl(meta)acrylate, 1-methylpiperidin-4-yl(meta)acrylate,
2,2,6,6-tetramethylpiperidin-4-yl(meta)acrylate,
1,2,2,6,6-pentamethylpiperidin-4-yl(meta)acrylate,
(piperidin-4-yl)methyl(meta)acrylate, and
2-(piperidin-4-yl)ethyl(meta)acrylate. Among these,
1,2,2,6,6-pentamethylpiperidin-4-yl methacrylate and
2,2,6,6-tetramethylpiperidin-4-yl methacrylate are preferable
because of being commercially available as FA-711MM and FA-712HM
(both are made by Hitachi Chemical Co., Ltd.), respectively.
In the case where (D) an acryl resin has a structural unit
represented by the formula (3), from the viewpoint of the
compatibility with an (A) component and the solubility to a
developing solution, it is preferable that the proportion of the
structural unit represented by the formula (3) is 0.3 to 10 mol %
with respect to the total amount of the (D) component; 0.4 to 6 mol
% is more preferable; and 0.5 to 5 mol % is still more
preferable.
It is preferable that a (D) component is the acryl resin further
having a structural unit represented by the following formula
(4):
##STR00021## wherein R.sup.7 represents a hydrogen atom or a methyl
group; and R.sup.8 represents an alkyl group having 4 to 20 carbon
atoms.
When a (D) component has a structural unit represented by the
formula (4), the dissolution inhibition of unexposed portions to a
developing solution can be improved more.
Examples of alkyl groups having 4 to 20 carbon atoms represented by
R.sup.8 include a butyl group, a pentyl group, a hexyl group, a
heptyl group, an octyl group, a nonyl group, a decyl group, an
undecyl group, a dodecyl group (it may be called a lauryl group), a
tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl
group, a heptadecyl group, an octadecyl group, a nonadecyl group,
and an eicosyl group. These groups may be a straight chain one or a
branched chain one.
From the viewpoint of more improving the sensitivity, the
resolution and the heat shock resistance, it is preferable that
R.sup.8 in the formula (4) is an alkyl group having 4 to 16 carbon
atoms; an alkyl group having 4 to 12 carbon atoms is more
preferable; and an alkyl group having 4 carbon atoms (n-butyl
group) is still more preferable.
Examples of monomers imparting a structural unit represented by the
formula (4) include alkyl(meth)acrylates. An example of the
alkyl(meth)acrylates includes a compound represented by the
following formula (12): CH.sub.2.dbd.C(R.sup.7)--COOR.sup.8 (12)
wherein R.sup.7 represents a hydrogen atom or a methyl group; and
R.sup.8 represents an alkyl group having 4 to 20 carbon atoms.
Examples of monomers represented by the formula (12) include
butyl(meth)acrylate, pentyl(meth)acrylate, hexyl(meth)acrylate,
heptyl(meth)acrylate, octyl(meth)acrylate, nonyl(meth)acrylate,
decyl(meth)acrylate, undecyl(meth)acrylate, dodecyl(meth)acrylate
(it may be called lauryl(meth)acrylate), tridecyl(meth)acrylate,
tetradecyl(meth)acrylate, pentadecyl(meth)acrylate,
hexadecyl(meth)acrylate, heptadecyl(meth)acrylate,
octadecyl(meth)acrylate, nanodecyl(meth)acrylate, and
eicosyl(meth)acrylate. These polymerizable monomers are used singly
or in a combination of two or more. Among these, from the viewpoint
of more improving the elongation at break and more decreasing the
elastic modulus, it is preferable that there is used
butyl(meth)acrylate, pentyl(meth)acrylate, hexyl(meth)acrylate,
heptyl(meth)acrylate, octyl(meth)acrylate, nonyl(meth)acrylate,
decyl(meth)acrylate, undecyl(meth)acrylate, or
dodecyl(meth)acrylate (it may be called lauryl(meth)acrylate).
In the case where (D) an acryl resin has a structural unit
represented by the formula (4), it is preferable that the
proportion of the structural unit represented by the formula (4) is
50 to 93 mol % with respect to the total amount of the (D)
component; 55 to 85 mol % is more preferable; and 60 to 80 mol % is
still more preferable. When the proportion of the structural unit
represented by the formula (4) is 50 to 93 mol %, the heat shock
properties of a patterned cured film can be improved more.
It is preferable that a (D) component is the acryl resin further
having a structural unit represented by the following formula
(5):
##STR00022## wherein R.sup.9 represents a hydrogen atom or a methyl
group.
When a (D) component has a structural unit represented by the
formula (5), the sensitivity can be improved more.
Monomers imparting a structural unit represented by the formula (5)
include acrylic acid and methacrylic acid.
In the case where (D) an acryl resin has a structural unit
represented by the formula (5), it is preferable that the
proportion of the structural unit represented by the formula (5) is
5 to 35 mol % with respect to the total amount of the (D)
component; 10 to 30 mol % is more preferable; and 15 to 25 mol % is
still more preferable. When the compositional ratio of structural
unit represented by the formula (5) is 5 to 35 mol %, the
compatibility with an (A) component and the developability can be
improved more.
A (D) component is obtained by blending, for example, a monomer
imparting a structural unit represented by the above formula (2),
and monomers imparting structural units represented by the formula
(3), (4) and (5), which are added as required, and stirring and as
required, heating the blend in a solvent such as ethyl lactate,
toluene or isopropanol.
Monomers to be used for the synthesis of (D) an acryl resin may
further include monomers other than the monomers imparting the
structural units represented by the formulae (2), (3), (4) and
(5).
Examples of such monomers include benzyl(meth)acrylate,
4-methylbenzyl(meth)acrylate, acrylonitrile, esters of vinyl
alcohols such as vinyl-n-butyl ether,
tetrahydrofurfuryl(meth)acrylate, glycidyl(meth)acrylate,
2,2,2-trifluoroethyl(meth)acrylate,
2,2,3,3-tetrafluoropropyl(meth)acrylate, .alpha.-bromo(meth)acrylic
acid, .alpha.-chloro(meth)acrylic acid, .beta.-furyl(meth)acrylic
acid, .beta.-styryl(meth)acrylic acid, maleic acid, maleic
anhydride, maleate monoesters such as and monomethyl maleate,
monoethyl maleate and monoisopropyl maleate, fumaric acid, cinnamic
acid, .alpha.-cyanocinnamic acid, itaconic acid, crotonic acid, and
propiolic acid. These monomers are used singly or in a combination
of two or more.
It is preferable that the weight-average molecular weight of a (D)
component is 2000 to 100000; 3000 to 60000 is more preferable; and
5000 to 50000 is still more preferable, and 10000 to 40000 is
especially preferable. When the weight-average molecular weight is
2000 or higher, the heat shock properties of a cured film can be
improved more; and when 100000 or lower, the compatibility with an
(A) component and the developability can be improved more. Here,
the weight-average molecular weight is a value obtained by a
measurement using gel permeation chromatography (GPC) and a
conversion using a standard polystyrene calibration curve.
From the viewpoint of the balance among the sensitivity, the
resolution, the adherence, the mechanical properties, and the
thermal shock resistance, it is preferable that the content of the
(D) component is 1 to 50 parts by mass with respect to 100 parts by
mass of the (A) component; 3 to 30 parts by mass is more
preferable; and 5 to 20 parts by mass is still more preferable.
<(E) Component>
A photosensitive resin composition according to the present
embodiment may contain a phenolic low molecular weight compound as
an (E) component. Thereby, while the dissolution inhibition of
unexposed portions of a resin film to an alkali developing solution
is maintained, the dissolution speed can be promoted. It is
preferable that an (E) component has about 3 to 4 benzene rings in
its molecule, and it is preferable that the molecular weight is 200
to 990. Here, the (E) component is different from an (A) component
or a (C) component.
From the viewpoint of the dissolution contrast to an alkali
developing solution, it is preferable that an (E) component is a
compound represented by one of the following formulae (13) to (15).
Among these, it is more preferable that an (E) component is a
compound represented by the following formula (14):
##STR00023## wherein R.sup.18 represents a hydrogen atom or a
methyl group; and a1 to f1 represent an integer of 0 to 3, the
total of d1 to f1 is 1 or more, the total of at and d1 is 5 or
less, the total of b1 and e1 is 5 or less, and the total of c1 and
f1 is 5 or less,
##STR00024## wherein R.sup.19 represents a hydrogen atom or a
methyl group; and a2 to c2 represent an integer of 0 to 3, d2 to f2
represent an integer of 1 to 3, the total of a2 and d2 is 5 or
less, the total of b2 and e2 is 5 or less, and the total of c2 and
f2 is 5 or less, or
##STR00025## wherein a3, c3, h and i represent an integer of 0 to
3, d3 and f3 represent an integer of 1 to 3, the total of a3 and d3
is 5 or less, the total of c3 and f3 is 5 or less, and the total of
h and i is 4 or less.
Examples of compounds represented by the formula (13) include
1,1,1-tris(4-hydroxyphenyl)methane,
1,1,1-tris(4-hydroxyphenyl)ethane,
1,1-bis(3,5-dimethyl-4-hydroxyphenyl)-1-(4-hydroxyphenyl)methane,
1,1-bis(2,3,5-trimethyl-4-hydroxyphenyl)-1-(2-hydroxyphenyl)methane,
1,1,1-tris(3-methyl-4-hydroxyphenyl)ethane,
1,1-bis(3-methyl-4-hydroxyphenyl)-1-(4-hydroxyphenyl)methane,
1,1-bis(3,5-dimethyl-4-hydroxyphenyl)-1-(3-hydroxyphenyl)methane,
1,1-bis(4,6-dimethyl-2-hydroxyphenyl)-1-(4-hydroxyphenyl)methane,
1,1-bis(3,4,6-trimethyl-2-hydroxyphenyl)-1-(2-hydroxyphenyl)methane,
1,1-bis(2,3,5-trimethyl-4-hydroxyphenyl)-1-(3-hydroxyphenyl)methane,
1,1-bis(2,3,5-trimethyl-4-hydroxyphenyl)-1-(4-hydroxyphenyl)methane,
1,1-bis(3-methyl-4-hydroxyphenyl)-1-(2-hydroxyphenyl)methane,
bis(2,5-dimethyl-4-hydroxyphenyl)-2-hydroxyphenylmethane,
bis(3,5-dimethyl-4-hydroxyphenyl)-2-hydroxyphenylmethane,
1,1-bis(3-methyl-4-hydroxyphenyl)-1-(3,4-dihydroxyphenyl)methane,
1,1-bis(3,5-dimethyl-4-hydroxyphenyl)-1-(3,4-dihydroxyphenyl)methane,
1,1-bis(2,3,5-trimethyl-4-hydroxyphenyl)-1-(3,4-hydroxyphenyl)methane,
1,1-bis(4-hydroxyphenyl)-1-(3,4-dihydroxyphenyl)methane,
1,1-bis(4-hydroxyphenyl)-1-(2-hydroxyphenyl)methane,
1,1-bis(2-methyl-4-hydroxyphenyl)-1-(2-hydroxyphenyl)methane,
1,1-bis(4,6-dimethyl-2-hydroxyphenyl)-1-(3-hydroxyphenyl)methane,
1,1-bis(3,4,6-trimethyl-2-hydroxyphenyl)-1-(3-hydroxyphenyl)methane,
1,1-bis(3,4,6-trimethyl-2-hydroxyphenyl)-1-(4-hydroxyphenyl)methane,
1,1-bis(4,6-dimethyl-4-hydroxyphenyl)-1-(3,4-dihydroxyphenyl)methane,
1,1-bis(3,4,6-trimethyl-2-hydroxyphenyl)-1-(3,4-dihydroxyphenyl)methane,
1,1-bis(5-methyl-2,3-dihydroxyphenyl)-1-(2-hydroxyphenyl)methane,
1,1-bis(4-hydroxyphenyl)-1-benzylethane,
1,1-bis(4-hydroxyphenyl)-1-benzylmethane,
1-(4-hydroxyphenyl)-1-(3,4-dihydroxyphenyl)-1-benzylethane,
1,1-bis(3-methyl-4-hydroxyphenyl)-1-benzylethane,
1,1-bis(2,3,5-trimethyl-4-hydroxyphenyl)-1-benzylmethane,
1,1-bis(2,3,6-trimethyl-4-hydroxyphenyl)-1-(4-methylbenzyl)methane,
and
1,1-bis(2,3,5-trimethyl-4-hydroxyphenyl)-1-(4-methylbenzyl)methane.
These compounds can be used singly or in a combination of two or
more.
Examples of compounds represented by the formula (14) include
1,1-bis(4-hydroxyphenyl)-1-[4-{1-(4-hydroxyphenyl)-1-methylethyl}phenyl]e-
thane,
1,1-bis(3,5-dimethyl-4-hydroxyphenyl)-1-[4-{1-(3,5-dimethyl-4-hydro-
xyphenyl)-1-methylethyl}phenyl]ethane and
1,1-bis(3-methyl-4-hydroxyphenyl)-1-[4-{1-(3-methyl-4-hydroxyphenyl)-1-me-
thylethyl}phenyl]ethane. These compounds can be used singly or in a
combination of two or more.
Examples of compounds represented by the formula (15) include
1-(3-methyl-4-hydroxyphenyl)-4-(4-hydroxyphenyl)benzene,
1-(3,5-dimethyl-4-hydroxyphenyl)-4-(4-hydroxyphenyl)benzene,
1,4-bis(3,5-dimethyl-4-hydroxyphenyl)benzene, and
1,4-bis(2,3,5-trimethyl-4-hydroxyphenyl)benzene. These compounds
can be used singly or in a combination of two or more.
From the viewpoint of suppressing residues after the development
and suppressing the pattern melt in heat curing, it is preferable
that the content of an (E) component is 1 to 40 parts by mass with
respect to 100 parts by mass of an (A) component; 3 to 35 parts by
mass is more preferable; and 5 to 30 parts by mass is still more
preferable.
<Other Components>
A photosensitive resin composition according to the present
embodiment may contain, other than the above (A) to (E), components
including a solvent, an elastomer, a compound that generates an
acid by heating, a dissolution promoter, a dissolution inhibitor, a
coupling agent, and a surfactant or a leveling agent.
(Solvent)
When a photosensitive resin composition according to the present
embodiment contains a solvent, there is attained the effect of
making coating on a substrate to be easy and being able to form a
coated film having a uniform thickness. Examples of the solvent
include .gamma.-butyrolactone, ethyl lactate, propylene glycol
monomethyl ether acetate, benzyl acetate, n-butylacetate,
ethoxyethylpropionate, 3-methylmethoxypropionate,
N-methyl-2-pyrrolidone, N,N-dimethylformamide,
N,N-dimethylacetamide, dimethylsulfoxide,
hexamethylphosphorylamide, tetramethylenesulfone, diethylketone,
diisobutylketone, methylamylketone, cyclohexan one,
propyleneglycolmonomethyl ether, propyleneglycolmonopropyl ether,
propyleneglycolmonobutyl ether and dipropyleneglycolmonomethyl
ether. These solvents can be used singly or in a combination of two
or more. Among these, from the viewpoint of the dissolvability and
the uniformity of a coated film, it is preferable that ethyl
lactate or propylene glycol monomethyl ether acetate is used.
(Elastomer)
As the elastomer, conventionally well-known ones can be used, but
it is preferable that the glass transition temperature (Tg) of a
polymer constituting an elastomer is 20.degree. C. or lower.
Examples of such an elastomer include styrene-based elastomers,
olefin-based elastomers, urethane-based elastomers, polyester-based
elastomers, polyamide-based elastomers, and silicone-based
elastomers. The elastomer may be microparticulate elastomers. These
elastomers can be used singly or in a combination of two or
more.
In the case where an elastomer is used, it is preferable that the
content thereof is 1 to 60 parts by mass with respect to 100 parts
by mass of an (A) component; 3 to 40 parts by mass is more
preferable; and 5 to 30 parts by mass is still more preferable.
(Compound that Generates an Acid by Heating)
By using a compound that generates an acid by heating, the acid is
enabled to be generated when a patterned resin film is heated, and
a reaction of an (A) component and a (C) component, that is, a
thermal crosslinking reaction is promoted and the heat resistance
of the patterned resin film is improved. Further since the compound
that generates the acid by heating generates the acid also by light
irradiation, the dissolvability of exposed portions to an alkali
aqueous solution increases. Therefore, the difference in the
dissolvability to an alkali aqueous solution between unexposed
portions and exposed portions becomes further large, more improving
the resolution.
It is preferable that such a compound that generates an acid by
heating is one to generate the acid, for example, by heating up to
50 to 250.degree. C. Specific examples of a compound that generates
an acid by heating include salts formed from a strong acid and a
base, such as onium salts, and imidosulfonates.
In the case where a compound that generates an acid by heating is
used, it is preferable that the content of the compound is 0.1 to
30 parts by mass with respect to 100 parts by mass of an (A)
component; 0.2 to 20 parts by mass is more preferable; and 0.5 to
10 parts by mass is still more preferable.
(Dissolution Promoter)
By blending a dissolution promoter in the above-mentioned positive
photosensitive resin composition, the dissolution speed of exposed
portions when the photosensitive resin composition is developed
with an alkali aqueous solution can be increased and the
sensitivity and the resolution can be improved. As the dissolution
promoter, conventionally well-known ones can be used. Specific
examples thereof include compounds having a carboxyl group,
sulfonic acid or a sulfoneamide group.
In the case where such a dissolution promoter is used, the content
of the dissolution promoter can be determined by the dissolution
speed to an alkali aqueous solution, and made to be 0.01 to 30
parts by mass with respect to 100 parts by mass of the (A)
component.
(Dissolution Inhibitor)
A dissolution inhibitor is a compound to inhibit the solubility of
an (A) component to an alkali aqueous solution, and is used in
order to control the remaining film thickness, the development time
and the contrast. Specific examples include diphenyliodonium
nitrate, bis(p-tert-butylphenyl)iodonium nitrate, diphenyliodonium
bromide, diphenyliodonium chloride, and diphenyliodonium iodide. In
the case where a dissolution inhibitor is used, from the viewpoint
of the sensitivity and the allowable width of the development time,
it is preferable that the content of the dissolution inhibitor is
0.01 to 20 parts by mass with respect to 100 parts by mass of the
(A) component; 0.01 to 15 parts by mass is more preferable; and
0.05 to 10 parts by mass is still more preferable.
(Coupling Agent)
By blending a coupling agent in a photosensitive resin composition,
the adhesion of a patterned cured film to be formed with a
substrate can be more raised. Examples of the coupling agent
include organosilane compounds and aluminum chelate compounds. An
example of the organosilane compound includes
ureapropyltrimethoxysilane.
In the case where a coupling agent is used, it is preferable that
the content thereof is 0.1 to 20 parts by mass with respect to 100
parts by mass of an (A) component; and 0.5 to 10 parts by mass is
more preferable.
(Surfactant or Leveling Agent)
By blending a surfactant or a leveling agent in a photosensitive
resin composition, the applicability can be improved more.
Specifically, for example, containing a surfactant or a leveling
agent can prevent the striation (unevenness of the film thickness)
more, and can improve the developability more. Examples of such a
surfactant or leveling agent include polyoxyethylene lauryl ether,
polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, and
polyoxyethylene octylphenol ether. Examples of commercially
available products include Megaface F171, F173, R-08 (trade name,
made by Dainippon Ink and Chemicals, Inc.), Fluorad FC430, FC431
(trade name, made by Sumitomo 3M Ltd.), and Organosiloxane Polymer
KP341, KBM303, KBM403, and KBM803 (trade name, made by Shin-Etsu
Chemical Co., Ltd.).
In the case where a surfactant or a leveling agent is used, it is
preferable that the content is 0.001 to 5 parts by mass with
respect to 100 parts by mass of the (A) component; and 0.01 to 3
parts by mass is more preferable.
A photosensitive resin composition according to the present
embodiment is capable of being developed using an alkali aqueous
solution of tetramethylammonium hydroxide (TMAH) or the like.
Further by using the above-mentioned photosensitive resin
composition according to the present embodiment, a patterned cured
film having a sufficiently high sensitivity and resolution, and the
good adherence and heat shock properties is enabled to be
formed.
[Patterned Cured Film and a Method for Producing the Patterned
Cured Film]
A patterned cured film according to the present invention can be
obtained by heating a photosensitive resin composition.
Then, a method for producing a patterned cured film will be
described. A method for producing a patterned cured film comprises
a step (applying and drying (film forming) step) of applying and
drying a photosensitive resin composition according to the present
embodiment on a part or the whole surface of a substrate to thereby
form a resin film, a step (exposing step) of exposing a part or the
whole surface of the resin film, a step (developing step) of
developing the resin film after the exposure with an alkali aqueous
solution to thereby form a patterned resin film, and a step (heat
treating step) of heating the patterned resin film.
<Applying and Drying (Film Forming) Step>
First, a photosensitive resin composition according to the present
embodiment is applied and dried on a substrate to thereby form a
resin film. In this step, first, a photosensitive resin composition
according to the present embodiment is rotationally applied on a
substrate of a glass, a semiconductor, a metal oxide insulator (for
example, TiO.sub.2, SiO.sub.2), a silicon nitride or the like by
using a spinner or the like to thereby form a coated film. The
thickness of the coated film is not especially limited, but it is
preferable that the thickness is 0.1 to 40 .mu.m. The substrate on
which the coated film has been formed is dried by using a hot
plate, an oven or the like. The drying temperature and the drying
time are not especially limited, but it is preferable that the
drying is carried out at 80 to 140.degree. C. for 1 to 7 min.
Thereby, a photosensitive resin film is formed on the support
substrate. The thickness of the photosensitive resin film is not
especially limited, but 0.1 to 40 .mu.m is preferable.
<Exposing Step>
Then, in the exposing step, the resin film formed on the substrate
is irradiated with active light rays such as ultraviolet rays,
visible light rays and radiation through a mask. In the
photosensitive resin composition according to the present
embodiment, since the (A) component is high in transparency to
i-line, the irradiation of i-line can suitably be used. After the
exposure, as required, post-exposure baking (PEB) may be carried
out from the viewpoint of improving the dissolution speed. In the
case where the post-exposure baking is carried out, it is
preferable that the temperature thereof is 70.degree. C. to
140.degree. C., and that the time thereof is 1 min to 5 min.
<Development Step>
In the development step, exposed portions of the resin film after
the exposure step are removed by a developing solution to thereby
pattern the resin film to obtain a patterned resin film. As the
developing solution, an alkali aqueous solution, for example, of
sodium carbonate, sodium hydroxide, potassium hydroxide, sodium
silicate, ammonia, ethylamine, diethylamine, triethylamine,
triethanolamine and tetramethylammonium hydroxide (TMAH), is
suitably used. It is preferable that the concentration of a base of
the aqueous solution is 0.1 to 10 mass %. Alcohols or a surfactant
may further be added to the developing solution and used. It is
preferable that each thereof can be blended in the range of 0.01 to
10 parts by mass with respect to 100 parts by mass of the
developing solution; and the range of 0.1 to 5 parts by mass
thereof is more preferable. A method of development using a
developing solution involves, for example, distributing the
developing solution on the photosensitive resin film by a method
such as a shower development, a spray development, an immersion
development or a paddle development, and leaving it to stand under
the condition of 18 to 40.degree. C. for 30 to 360 sec. The
patterned resin film is washed by water washing and spin drying
after the being left.
<Heat Treating Step>
Then, in the heat treating step, by heat treating the patterned
resin film, a patterned cured film can be formed. From the
viewpoint of preventing damage due to heat to semiconductor
apparatuses, it is preferable that the heating temperature in the
heat treating step is 250.degree. C. or lower; 225.degree. C. or
lower is more preferable; and 140 to 200.degree. C. is still more
preferable.
The heat treatment can be carried out, for example, using an oven
such as a quartz tube oven, a hot plate, a rapid thermal annealer,
a vertical diffusion oven, an infrared curing oven, an
electron-beam curing oven, a microwave curing oven. Although the
atmosphere for the heat treatment can be selected from either of
the air and an inert atmosphere such as nitrogen, it is desirable
that the heat treatment is carried out in nitrogen, because of
being able to prevent the oxidation of the pattern. Since the
above-mentioned preferable range of the heating temperature is
lower than conventional heating temperatures, the damage to support
substrates and semiconductor apparatuses can be suppressed small.
Therefore, by using the producing method of a resist pattern
according to the present embodiment, electronic devices can be
produced in a high yield. The heating temperature leads to the
energy saving of the process. The use of the positive
photosensitive resin composition according to the present
embodiment, since the volume shrinkage (curing shrinkage) in the
heat treatment step, as would be seen in the use of photosensitive
polyimide and the like, is low, can further prevent the decrease in
the dimensional accuracy.
The heat treatment time in the heat treatment step suffices if
being a time enough to cure the positive photosensitive resin
composition, but about 5 hours or shorter is preferable in the
balance with the working efficiency.
The heat treatment can also be carried out by using, in addition to
the above-mentioned ovens, a microwave curing apparatus or a
frequency-variable microwave curing apparatus. The use of these
apparatuses allows effective heating of a photosensitive resin film
alone with the temperature of substrates and semiconductor
apparatuses being held, for example, at 200.degree. C. or lower
(see J. Photopolym. Sci. Technol., 18, 327-332 (2005)).
According to the above-mentioned method for producing a patterned
cured film according to the present embodiment, the patterned cured
film having a sufficiently high sensitivity and resolution, and the
excellent adherence and heat shock properties can be obtained.
[Interlayer Insulating Layer, Surface Protecting Layer]
The patterned cured film obtained by the method for producing a
patterned cured film according to the present embodiment can be
used as an interlayer insulating layer or a surface protecting
layer of a semiconductor element.
[Semiconductor Element]
A semiconductor element according to the present embodiment has the
interlayer insulating layer or the surface protecting layer
according to the present embodiment. The semiconductor element
according to the present embodiment is not especially limited, but
refers to a memory, a package and the like having a multilayer
wiring structure, a rewiring structure and the like.
Here, one example of a producing step of a semiconductor element
will be described based on the drawings. FIGS. 1 to 5 are schematic
perspective views and schematic end views illustrating one
embodiment of the producing step of a semiconductor element having
a multilayer wiring structure. In FIGS. 1 to 5, (a) are schematic
perspective views, and (b) are schematic perspective views
illustrating Ib-Ib to Vb-Vb end surfaces in the corresponding
(a).
First, a structural body 100 shown in FIG. 1 is prepared. The
structural body 100 comprises a semiconductor substrate 1 such as a
Si substrate having circuit elements, a protecting film 2 such as a
silicon oxide film having a predetermined pattern where the circuit
elements are exposed and covering the semiconductor substrate 1, a
first conductor layer 3 formed on the exposed circuit elements, and
an interlayer insulating layer 4 formed as a film on the protecting
film 2 and the first conductor layer 3 by a spin coat method or the
like and composed of a polyimide resin or the like.
Then, a photosensitive resin layer 5 having window parts 6A is
formed on the interlayer insulating layer 4 to thereby obtain a
structural body 200 shown in FIG. 2. The photosensitive resin layer
5 is formed by applying a photosensitive resin such as a
chlorinated rubber-based, a phenol novolac-based, a
polyhydroxystyrene-based or a polyacrylate ester-based one, by a
spin coat method. The window parts 6A are formed by a well-known
photo-lithographic technology so that predetermined portions of the
interlayer insulating layer 4 are exposed.
The interlayer insulating layer 4 is etched to thereby form window
parts 6B, and thereafter, the photosensitive resin layer 5 is
removed to thereby obtain a structural body 300 shown in FIG. 3.
The etching of the interlayer insulating layer 4 can use dry
etching means using a gas such as oxygen or carbon tetrafluoride.
By this etching, portions of the interlayer insulating layer 4
corresponding to the window parts 6A are selectively removed to
thereby obtain the interlayer insulating layer 4 provided with the
window parts 6B so that the first conductor layer 3 is exposed.
Then, the photosensitive resin layer 5 is removed using an etching
solution which does not corrode the first conductor layer 3 exposed
from the window parts 6B, but corrodes the photosensitive resin
layer 5 only.
A second conductor layer 7 is further formed on portions
corresponding to the window parts 6B to thereby obtain a structural
body 400 shown in FIG. 4. The formation of the second conductor
layer 7 can use a well-known photo-lithographic technology. The
second conductor layer 7 and the first conductor layer 3 are
thereby electrically connected.
Finally, a surface protecting layer 8 is formed on the interlayer
insulating layer 4 and the second conductor layer 7 to thereby
obtain a semiconductor element 500 shown in FIG. 5. In the present
embodiment, the surface protecting layer 8 is formed as follows.
First, the above-mentioned photosensitive resin composition is
applied on the interlayer insulating layer 4 and the second
conductor layer 7 by a spin coat method, and dried to thereby form
a photosensitive resin film. Then, light irradiation is carried out
through a mask on whose predetermined portions a pattern
corresponding to window parts 6C is drawn, and thereafter, the
resin film after the exposure is developed with an alkali aqueous
solution to thereby form a patterned resin film. Thereafter, the
patterned resin film is heated to be cured to thereby form a
patterned cured film to be used as the surface protecting layer 8.
The surface protecting layer 8 protects the first conductor layer 3
and the second conductor layer 7 from stresses, .alpha. rays and
the like from the outside; and the semiconductor element 500 using
the surface protecting layer 8 according to the present embodiment
is excellent in the reliability.
In the above-mentioned embodiment, a producing method of a
semiconductor element having a two-layer wiring structure was
described, but in the case of forming a multilayer wiring structure
of two or more layers, the each layer can be formed by repeatedly
carrying out the above-mentioned steps. That is, a multilayer
pattern is allowed to be formed by repeating the each step of
forming the interlayer insulating layer 4 and the each step of
forming the surface protecting layer 8. Here, in the above example,
not only the surface protecting layer 8 but also the interlayer
insulating layer 4 are allowed to be formed using the
photosensitive resin composition according to the present
embodiment.
An electronic device according to the present embodiment can have,
not limited to the structure having a surface protecting layer, a
cover coat layer or an interlayer insulating layer formed using the
above-mentioned positive photosensitive resin composition, one of
various structures.
FIGS. 6 and 7 are schematic cross-sectional views illustrating one
embodiment of a semiconductor element having a rewiring structure.
The photosensitive resin composition according to the present
embodiment, since being excellent in the stress relaxation, the
adhesion and the like, can be used in semiconductor elements having
a rewiring structure recently developed as shown in FIGS. 6 and
7.
FIG. 6 is a schematic cross-sectional diagram showing a wiring
structure as one embodiment of a semiconductor element. The
semiconductor element 600 shown in FIG. 6 comprises a silicon
substrate 23, an interlayer insulating layer 11 provided on one
surface side of the silicon substrate 23, an A1 wiring layer 12
formed on the interlayer insulating layer 11 and having a pattern
containing a pad portion 15, an insulating layer 13 (for example,
P--SiN layer) and a surface protecting layer 14 successively
stacked on the interlayer insulating layer 11 and the A1 wiring
layer 12 while an opening is formed on the pad portion 15, an
island-shaped core 18 disposed in the vicinity of the opening on
the surface protecting layer 14, and a rewiring layer 16 extending
on the surface protecting layer 14 so as to contact with the pad
portion 15 in the opening of the insulating layer 13 and the
surface protecting layer 14 and to contact with a surface of the
core 18 on the opposite side thereof to the surface protecting
layer 14. Further, the semiconductor element 600 further comprises
a cover coat layer 19 formed covering the surface protecting layer
14, the core 18 and the rewiring layer 16 and having an opening
formed on a portion of the rewiring layer 16 on the core 18, a
conductive ball 17 connected with the rewiring layer 16 through a
barrier metal 20 interposed therebetween in the opening of the
cover coat layer 19, a collar 21 holding the conductive ball, and
an underfill 22 provided on the cover coat layer 19 around the
conductive ball 17. The conductive ball 17 is used as an external
connection terminal, and is formed of a solder, gold or the like.
The underfill 22 is provided in order to relax the stress when the
semiconductor element 600 is mounted.
In the semiconductor element 700 of FIG. 7, an A1 wiring layer (not
shown in figure) and a pad portion 15 of the A1 wiring layer are
formed on a silicon substrate 23; an insulating layer 13 is formed
on the lower part thereof; and a surface protecting layer 14 for
elements is further formed. A rewiring layer 16 is formed on the
pad portion 15; and the rewiring layer 16 extends up to the upper
part of a connection part 24 with a conductive ball 17. A cover
coat layer 19 is further formed on the surface protecting layer 14.
The rewiring layer 16 is connected with the conductive ball 17
through a barrier metal 20.
In the semiconductor elements of FIGS. 6 and 7, the photosensitive
resin composition can be used as a material not only for forming
the interlayer insulating layer 11 and the surface protecting layer
14, but also for forming the cover coat layer 19, the core 18, the
collar 21, the underfill 22, and the like. Since a patterned cured
film using the photosensitive resin composition according to the
present embodiment is excellent in the adhesion with a metal layer
such as the A1 wiring layer 12 or the rewiring layer 16, and high
in the stress relaxation effect, a semiconductor element using the
patterned cured film for the interlayer insulating layer 11, the
surface protecting layer 14, the cover coat layer 19, the core 18,
the collar 21 of a solder or the like, the underfill 22 used in
flip chips, and the like becomes remarkably excellent in the
reliability.
It is suitable that the photosensitive resin composition according
to the present embodiment is used for the interlayer insulating
layer 11, the surface protecting layer 14 and/or the cover coat
layer 19 of the semiconductor elements having the rewiring layer 16
in FIGS. 6 and 7.
It is preferable that the film thicknesses of the interlayer
insulating layer 11, the surface protecting layer 14 and the cover
coat layer 19 are 3 to 20 .mu.m; and 5 to 15 .mu.m is more
preferable.
[Electronic Device]
An electronic device according to the present embodiment has the
semiconductor element according to the present embodiment. The
electronic device refers to one containing the above-mentioned
semiconductor element, and examples thereof include cell phones,
smartphones, tablet computers, personal computers, and hard disc
suspensions.
As described hitherto, in the photosensitive resin composition
according to the present embodiment, the white turbidity of the
photosensitive resin composition is sufficiently suppressed; the
haze value of a patterned cured film to be formed is made low; and
in the producing step of a semiconductor element after the
formation of the patterned cured film, the alignment is easily
carried out. Further a patterned cured film formed using the
photosensitive resin composition according to the present
embodiment is excellent in the mechanical properties and low in the
changing rates of mechanical properties after being left at a high
temperature and after a thermal shock test. Further the
photosensitive resin composition according to the present
embodiment can provide a semiconductor element and an electronic
device excellent in the reliability.
EXAMPLES
Hereinafter, the present invention will be described specifically
based on Examples, but the present invention is not limited
thereto.
Materials used in the present Examples will be shown in the
below.
[(A) Component]
A1: 100 parts by mass in total of p-t-butoxystyrene and styrene in
a molecular ratio of 85:15 was prepared; these were dissolved in
150 parts by mass of propylene glycol monomethyl ether; and the
polymerization was carried out in a nitrogen atmosphere at a
reaction temperature being held at 70.degree. C., for 10 hours by
using 4 parts by mass of azobisisobutyronitrile, under stirring at
a stirring rotation frequency of about 160 rpm. Thereafter,
sulfuric acid was added to the reaction solution and allowed to
react at a reaction temperature being held at 90.degree. C. for 10
hours to thereby deprotect p-t-butoxystyrene and convert it to
hydroxystyrene. Ethyl acetate was added to the obtained copolymer;
water washing was repeated five times; an ethyl acetate phase was
collected, and the solvent was removed to thereby obtain a
p-hydroxystyrene/styrene copolymer A1. The weight-average molecular
weight (Mw) in terms of polystyrene of the copolymer A1 was 10000.
As a result of a .sup.13C-NMR analysis, the copolymerization
molecular ratio of p-hydroxystyrene and styrene was 85:15. A2: a
p-hydroxystyrene homopolymer A2 was obtained as in the synthesis
example 1, except for dissolving 100 parts by mass of
p-t-butoxystyrene alone in 150 parts by mass of propylene glycol
monomethyl ether. The weight-average molecular weight of the
homopolymer A2 was 10000. A3: a copolymer of
4-hydroxystyrene/methyl methacrylate in 50/50 (in molecular
ratio)(weight-average molecular weight: 10000, made by Maruzen
Petrochemical Co., Ltd., trade name: "Maruka Lyncur CMM"). A'4: a
cresol novolac resin (cresol/formaldehyde novolac resin,
m-cresol/p-cresol (in molecular ratio): 60/40, weight-average
molecular weight: 12000, made by Asahi Organic Chemicals Industry
Co., Ltd., trade name: "EP4020G").
Here, the weight-average molecular weights were determined by using
gel permeation chromatography (GPC) and a conversion in terms of
standard polystyrene.
Specifically, the weight-average molecular weight was measured by
the following apparatus under the following condition.
Measuring apparatus: a detector: L4000UV, made by Hitachi, Ltd.; a
pump: L6000, made by Hitachi, Ltd.; and C-R4A Chromatopac, made by
Shimadzu Corp.
Measuring condition: columns: Gelpack GL-S300MDT-5 (two columns);
an eluent: THF, LiBr (0.03 mol/l), H.sub.3PO.sub.4 (0.06 mold); the
flow rate: 1.0 ml/min; the detector: UV 270 nm; and the measurement
was carried out using a solution in which a solvent [THF/DMF (in
volume ratio): 1/1] was 1 ml with respect to 0.5 mg of a
sample.
[(B) Component]
B1: a 1-naphthoquinone-2-diazide-5-sulfonate ester of
1,1-bis(4-hydroxyphenyl)-1-[4-{1-(4-hydroxyphenyl)-1-methylethyl}phenyl]e-
thane (esterification rate: about 90%, made by AZ Electronic
Materials SA, trade name: "TPPA528").
B2: a 1-naphthoquinone-2-diazide-5-sulfonate ester of
tris(4-hydroxyphenyl)methane (esterification rate: about 95%).
[(C) Component]
C1: hexakis(methoxymethyl)melamine (made by Sanwa Chemical Co.,
Ltd., trade name: "Nikalac MW-30HM", a compound represented by the
following formula (C1)).
##STR00026## C2: 1,1-bis
{3,5-bis(methoxymethyl)-4-hydroxyphenyl}methane (made by Honshu
Chemical Industry Co., Ltd., trade name: "TMOM-pp-BPF", a compound
represented by the following formula (C2)).
##STR00027##
[(D) Component]
D1: 55 g of ethyl lactate was weighed in a 100-ml three-necked
flask equipped with a stirrer, a nitrogen introducing tube and a
thermometer; and separately weighed polymerizable monomers (34.7 g
of n-butyl acrylate (BA), 2.2 g of lauryl acrylate (LA), 3.9 g of
acrylic acid (AA), 2.6 g of hydroxybutyl acrylate (HBA) and 1.7 g
of 1,2,2,6,6-pentamethylpiperidin-4-yl methacrylate (trade name:
FA-711MM, made by Hitachi Chemical Co., Ltd.)), and 0.29 g of
azobisisobutyronitrile (AIBN) were added. Dissolved oxygen was
removed by making nitrogen gas flow at a flow volume of 400 ml/min
for 30 min under stirring at a stirring rotation frequency of about
160 rpm at room temperature. Thereafter, the inflow of the nitrogen
gas was stopped; and the flask was sealed, and heated to 65.degree.
C. over about 25 min in a constant-temperature water bath. The
temperature was held for 10 hours to carry out the polymerization
reaction to thereby obtain an acryl resin D1. This polymerization
rate was 99%. The weight-average molecular weight of the D1 was
about 22000. Here, the molecular ratio of the polymerizable
monomers in the acryl resin D1 was as follows.
BA/LA/AA/HBA/FA711MM=75.5/2.5/15/5/2 (mol %)
D2 to D4, D'5, D6 to D9: acryl resins D2 to D4, D'5, D6 to D9 were
synthesized as in the synthesis method of D1, except for using
polymerizable monomers in blend amounts indicated in Table 1,
respectively. The weight-average molecular weights of the
synthesized acryl resins D2 to D4, D'5, D6 to D9 are shown in Table
1.
Here, the weight-average molecular weight of the (D) component was
determined by the same method as in the (A) component.
TABLE-US-00001 TABLE 1 Polymerizable Monomer D1 D2 D3 D4 D'5 D6 D7
D8 D9 FA-711MM 1.7 g 1.7 g 1.6 g -- 1.7 g 1.6 g 1.7 g 1.7 g -- (20
mmol) (20 mmol) (20 mmol) (20 mmol) (20 mmol) (20 mmol) (20 mmol)
BA 34.7 g 32.8 g 31.0 g 34.3 g 33.7 g 37.1 g 31.0 g 33.2 g -- (755
mmol) (730 mmol) (705 mmol) (665mmol) (730 mmol) (880 mmol) (680
mmol) (730 mmol) LA 2.2 g 4.2 g 6.2 g 4.3 g 4.3 g 4.0 g 4.3 g 4.3 g
-- (25 mmol) (50 mmol) (75 mmol) (50 mmol) (50 mmol) (50 mmol) (50
mmol) (50 mmol) AA 3.9 g 3.8 g 3.7 g 3.9 g 5.2 g -- 3.8 g 3.8 g --
(150 mmol) (150 mmol) (150 mmol) (150 mmol) (200 mmol) (150 mmol)
(150 mmol) HEA -- -- -- -- -- -- 4.1 g 2.1 g -- (100 mol) (50 mmol)
HBA 2.6 g 2.5 g 2.5 g 2.6 g -- 2.4 g -- -- 50.0 g (50 mmol) (50
mmol) (50 mmol) (50 mmol) (50 mmol) (1000 mmol) Weight-Average
22000 22000 22000 32000 22000 22000 22000 22000 22000 Molecular
Weight FA-711MM: 1,2,2,6,6-pentamethylpiperidin-4-yl methacrylate
(made by Hitachi Chemical Co., Ltd.) BA: n-butyl acrylate LA:
lauryl acrylate AA: acrylic acid HEA: hydroxyethyl acrylate HBA:
hydroxybutyl acrylate
Examples 1 to 12, and Comparative Examples 1 to 3
(A) to (D) components in blend amounts indicated in Table 2, 120
parts by mass of ethyl lactate as a solvent, and 2 parts by mass of
a 50% methanol solution of ureapropyltriethoxysilane as a coupling
agent were blended, and the blend was subjected to a pressure
filtration using a Teflon.RTM. filter of 3 .mu.m in pore to thereby
prepare photosensitive resin compositions of Examples 1 to 12 and
Comparative Examples 1 to 3.
<Evaluation of the Photosensitive Resin Compositions>
The photosensitive resin compositions of Examples 1 to 12 and
Comparative Examples 1 to 3 were evaluated for the following. The
results are shown in Table 2.
(Remaining Film Ratio, Sensitivity, and Resolution)
The photosensitive resin compositions obtained in Examples 1 to 12
and Comparative Examples 1 to 3 were each spin coated on the
silicon substrate, and heated at 120.degree. C. for 4 min to
thereby form a coated film of about 11 to 13 .mu.m in thickness.
Then, the coated film was subjected to a reduction projection
exposure using the i-line (365 nm) through a mask having square
hole patterns of 1 .mu.m.times.1 .mu.m to 100 .mu.m.times.100 .mu.m
by using an i-line stepper (made by Canon Inc., trade name:
"FPA-3000iW"). The exposure was carried out by varying the exposure
amount from 100 to 1520 mJ/cm.sup.2 stepwise by 20 mJ/cm.sup.2.
After the exposure, the coated film was subjected to a development
using a 2.38% aqueous solution of tetramethylammonium hydroxide
(TMAH). The remaining film ratio of unexposed portions after the
development was about 80 to 99% of the film thickness before the
development. Then, since the coated film was of a positive
photosensitive resin composition, the remaining film ratio did not
depend on the exposure amount. Here, the remaining film ratio was
calculated by the following expression. Remaining film ratio (%)=(a
film thickness of the coated film after the development/a film
thickness of the coated film before the development).times.100
Thereafter, the remaining film was rinsed with water; and the
minimum exposure amount capable of forming the 100 .mu.m.times.100
.mu.m square hole pattern was taken as the sensitivity. Further,
the size (the length of one side) of a minimum one out of the
opened square hole patterns in the above range of the exposure
amounts was taken as an index of the resolution. The lower the
sensitivity and the resolution, the better. The results are shown
in Table 2.
Thereafter, the resist patterns were heat treated (cured) in
nitrogen, at a temperature of 200.degree. C. (temperature-rise
time: 1.5 hours) for 2 hours by using a vertical diffusion oven
(made by Koyo Thermo System Co., Ltd., trade name: ".mu.-TF"), and
the resolution after the curing was measured. The evaluation method
was the same as in the resolution before the curing.
(Curing Shrinkage Percentage)
The photosensitive resin compositions obtained in Examples 1 to 12
and Comparative Examples 1 and 3 were each spin coated on the
silicon substrate, and heated at 120.degree. C. for 4 min to
thereby form a coated film of about 12 to 14 .mu.m in thickness.
Thereafter, the coated film was subjected to an exposure in an
exposure amount two times the minimum exposure amount in the entire
wavelength through a mask by using a proximity aligner (made by
Canon Corp., trade name: "PLA-600FA"). After the exposure, the
resin film was subjected to a development using a 2.38% aqueous
solution of TMAH to thereby obtain a resist pattern of 10 mm in
width. Thereafter, the resist pattern was heat treated (cured) in
nitrogen at a temperature of 200.degree. C. (temperature-rise time:
1.5 hours) for 2 hours by using a vertical diffusion oven (made by
Koyo Thermo System Co., Ltd., trade name: ".mu.-TF") to thereby
obtain a cured film of about 10 .mu.m in thickness. Here, the
curing shrinkage percentage was calculated by the following
expression. Curing shrinkage percentage (%)=[1-(a film thickness
after curing/a film thickness before curing)].times.100
The results are shown in Table 2.
(Elongation at Break after Curing, Elastic Modulus after
Curing)
A cured film having the film thickness obtained by the same method
as in the above-mentioned evaluation of the curing shrinkage
percentage was peeled off the silicon substrate; and the elongation
at break (EL) and the elastic modulus (YM) of the peeled-off cured
film were measured by Autograph AGS-H100N, made by Shimadzu Corp.
The width of the sample was 10 mm; the film thickness was about 10
.mu.m; and the distance between chucks was made to be 20 mm. The
tension rate was set at 5 mm/min; and the measurement temperature
was made nearly at room temperature (20.degree. C. to 25.degree.
C.). Averages of measurement values of 5 test pieces obtained from
the cured film obtained in the same condition were taken as the
elongation at break after the curing and the elastic modulus after
the curing. It is preferable that the elongation at break after the
curing is large; and it is more preferable that the elongation is
5% or larger. It is preferable that the elastic modulus after the
curing is small; and it is preferable that the elastic modulus is 3
GPa or smaller. The results are shown in Table 2.
(Elongation at Break after being Left at a High Temperature,
Elastic Modulus after being Left at a High Temperature)
A cured film of about 10 .mu.m in film thickness obtained by the
same method as in the above-mentioned evaluation of the curing
shrinkage percentage was left for 1000 hours in a box-type drier
(VOS-300VD, made by Tokyo Rikakikai Co., Ltd.) of 150.degree. C.,
and thereafter peeled off the silicon substrate; and the elongation
at break and the elastic modulus of the peeled-off cured film were
measured by Autograph AGS-H100N, made by Shimadzu Corp. The width
of the sample was 10 mm; the film thickness was about 10 .mu.m; and
the distance between chucks was made to be 20 mm. The tension rate
was set at 5 mm/min; and the measurement temperature was made
nearly at room temperature (20.degree. C. to 25.degree. C.).
Averages of measurement values of 5 or more test pieces obtained
from the cured film obtained in the same condition were taken as
the elongation at break after being left at a high temperature and
the elastic modulus after being left at a high temperature. It is
preferable that the elongation at break after being left at a high
temperature is large; and it is more preferable that the elongation
is 5% or larger. It is preferable that the elastic modulus after
being left at a high temperature is low; and it is preferable that
the elastic modulus is 3 GPa or lower. It is preferable that the
difference between the elongation at break after being left at a
high temperature and the elongation at break after the curing is
smaller. It is also preferable that the difference between the
elastic modulus after being left at a high temperature and the
elastic modulus after the curing is smaller. The results are shown
in Table 2.
(Elongation at Break after a Thermal Shock Test, Elastic Modulus
after a Thermal Shock Test)
A cured film of about 10 .mu.m in film thickness obtained by the
same method as in the above-mentioned evaluation of the curing
shrinkage percentage was subjected to a thermal shock test of 1000
cycles with each cycle being -40.degree. C./30 min to 125.degree.
C./30 min by using an ETAC WINTECH NT1010 (made by Kusumoto
Chemicals, Ltd.), and thereafter peeled off the silicon substrate;
and the elongation at break and the elastic modulus of the
peeled-off cured film were measured by Autograph AGS-H100N, made by
Shimadzu Corp. The width of the sample was 10 mm; the film
thickness was about 10 .mu.m; and the distance between chucks was
made to be 20 mm. The tension rate was set at 5 mm/min; and the
measurement temperature was made nearly at room temperature
(20.degree. C. to 25.degree. C.). Averages of measurement values of
5 test pieces obtained from the cured film obtained in the same
condition were taken as the elongation at break after a thermal
shock test and the elastic modulus after a thermal shock test. It
is preferable that the elongation at break after a thermal shock
test is large; and it is more preferable that the elongation is 5%
or larger. It is preferable that the elastic modulus after a
thermal shock test is low; and it is preferable that the elastic
modulus is 3 GPa or lower. It is also preferable that the
difference between the elongation at break after a thermal shock
test and the elongation at break after the curing is smaller. It is
also preferable that the difference between the elastic modulus
after a thermal shock test and the elastic modulus after the curing
is smaller. The results are shown in Table 2.
(White Turbidity of the Resin)
The photosensitive resin compositions obtained in Examples 1 to 12
and Comparative Examples 1 to 3 were visually observed, and if the
resin was transparent, it was taken as A; when being slightly
cloudy, as B; and when being heavily cloudy, as C. If the white
turbidity of the resin is A or B, when a semiconductor element
having a patterned cured film formed by using the resin is
produced, marks for alignment made on a substrate can be
recognized. The results are shown in Table 2.
(Haze)
The photosensitive resin compositions obtained in Examples 1 to 12
and Comparative Examples 1 to 3 were each spin coated on a glass
substrate, heated at 120.degree. C. for 3 min to thereby form a
coated film of 10 to 11 .mu.m in film thickness; and the haze value
(haze after the coating) of the film was measured by a haze meter
(made by Nippon Denshoku Industries Co., Ltd., trade name:
"NDH5000"). The haze value is a numerical value indicating a degree
of cloudiness, and refers to a proportion of the diffusion light to
the total reflection light. The calculation expression of the haze
value is as follows. Haze=a diffusion rate/a total light
transmittance.times.100
It is preferable that the haze value is lower than 7.0%; lower than
5.0% is more preferable; lower than 1.0% is still more preferable.
If the haze value is 7.0% or higher, when a semiconductor element
is produced, marks for alignment made on a substrate can hardly be
recognized. The results are shown in Table 2.
TABLE-US-00002 TABLE 2 Com- Example Comparative Example ponent
Material 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 (A) A1 80 80 80 80 80 80
80 -- -- 80 80 80 100 -- 80 A2 -- -- -- -- -- -- -- 80 -- -- -- --
-- -- -- A3 -- -- -- -- -- -- -- -- 80 -- -- -- -- -- A4 -- -- --
-- -- -- -- -- -- -- -- -- -- 80 -- (B) B1 20 20 20 20 20 20 20 20
20 -- 20 20 20 15 20 B2 -- -- -- -- -- -- -- -- -- 20 -- -- -- --
-- (C) C1 5 5 5 5 5 5 5 5 5 5 -- 5 5 15 5 C2 -- -- -- -- -- -- --
-- -- -- 5 -- -- -- -- (D) D1 20 -- -- -- -- -- -- 20 20 20 20 --
-- 20 -- D2 -- 20 -- -- -- -- -- -- -- -- -- -- -- -- -- D3 -- --
20 -- -- -- -- -- -- -- -- -- -- -- -- D4 -- -- -- 20 -- -- -- --
-- -- -- -- -- -- -- D'5 -- -- -- -- -- -- -- -- -- -- -- -- -- --
20 D6 -- -- -- -- 20 -- -- -- -- -- -- -- -- -- -- D7 -- -- -- --
-- 20 -- -- -- -- -- -- -- -- -- D8 -- -- -- -- -- -- 20 -- -- --
-- -- -- -- -- D9 -- -- -- -- -- -- -- -- -- -- -- 20 -- -- --
Remaining Film Ratio (%) 97 94 90 82 98 90 93 75 95 92 95 100 99 99
93 Sensitivity [mJ/cm.sup.2] 460 440 420 660 .gtoreq.1520 440 420
280 560 600 520 320 no opening 400 460 made Reso- After 2 2 2 5 --
2 2 2 2 3 3 10 -- 5 2 lution Development [.mu.m] After Curing 2 2 2
5 -- 2 2 2 2 3 3 10 -- 15 2 Curing Shrinkage 10 10 10 10 9 10 10 10
12 10 12 10 10 14 10 Percentage [%] Elon- After Curing 55 49 52 38
19 29 20 23 18 28 13 28 4 40 8 gation at After Being Left at a 40
36 38 24 16 22 15 16 15 19 7 20 3 10 4 Break High Temperature [%]
After Thermal Shock 42 39 40 26 16 23 15 18 15 21 10 20 3 17 5
Elastic Test After Curing 2.4 22 2.0 1.9 2.3 2.4 2.5 2.4 2.2 2.5
2.6 2.7 3.6 2.1 2.7 Modulus After Being Left at a 2.5 2.3 2.1 2.0
2.4 2.5 2.6 2.6 2.3 2.6 2.7 2.8 3.7 2.7 2.9 [GPa] High Temperature
After Thermal 2.4 2.2 2.0 1.9 2.3 2.4 2.5 2.5 2.2 2.5 2.6 2.8 3.7
2.6 2.8 Shock Test White Turbidity A A A A A A B A A A A A A A C
Haze [%] 0.3 0.3 0.4 0.5 0.4 0.4 1.2 0.5 0.5 0.6 0.5 0.3 0.2 2
15.6
As is clear from Table 2, the photosensitive resin compositions of
Examples 1 to 12 were good in the sensitivity, could sufficiently
suppress white turbidity, were excellent in the mechanical
properties (elongation at break and elastic modulus) of the formed
patterned cured films, and were low in the changing rates of the
mechanical properties after being left at a high temperature and
after a thermal shock test. By contrast, in Comparative Example 1,
in which no (D) component was used, the mechanical properties of
the formed patterned cured film were inferior. In Comparative
Example 2, in which a cresol novolac resin A'4 was used, the
changing rates of the mechanical properties after being left at a
high temperature and after a thermal shock test became high.
Further in Comparative Example 3, in which an acryl resin D'5
having no structural unit represented by the formula (2) was used,
the resin became cloudy, and also the haze value of the formed
patterned cured film was high.
[(D) Component]
D10: 55 g of ethyl lactate was weighed in a 100-ml three-necked
flask equipped with a stirrer, a nitrogen introducing tube and a
thermometer; and separately weighed polymerizable monomers (35.44 g
of n-butyl acrylate (BA), 2.17 g of lauryl acrylate (LA), 3.91 g of
acrylic acid (AA), 2.61 g of hydroxybutyl acrylate (HBA) and 0.87 g
of 1,2,2,6,6-pentamethylpiperidin-4-yl methacrylate (trade name:
FA-711MM, made by Hitachi Chemical Co., Ltd.)), and 0.30 g of
azobisisobutyronitrile (AIBN) were added. While the mixture was
stirred at room temperature at a stirring rotation frequency of
about 160 rpm, nitrogen gas was made to flow at a flow volume of
400 ml/min for 30 min to thereby remove dissolved oxygen.
Thereafter, the inflow of the nitrogen gas was stopped; the flask
was sealed; and the reaction solution was heated up to 65.degree.
C. in about 25 min in a constant-temperature water bath. The
polymerization reaction was carried out with the temperature being
held for 10 hours, to thereby obtain an acryl resin D10. The
polymerization rate at this time was 99%. The weight-average
molecular weight of the D10 as measured by the above-mentioned
method was about 28000.
The molecular ratio of the polymerizable monomers in the acryl
resin D10 was as follows.
BA/LA/AA/HBA/FA711MM=76.5/2.5/15/5/1 (mol %)
[(E) Component]
E1:
1,1-bis(4-hydroxyphenyl)-1-[4-{1-(4-hydroxyphenyl)-1-methylethyl}phen-
yl]ethane (made by Honshu Chemical Industry Co., Ltd., trade name:
"TrsP-PA-MF", a compound corresponding to the formula (14)).
E2: 1,1,1-tris(4-hydroxyphenyl)methane (a compound corresponding to
the formula (13)).
E3: 1-(3-methyl-4-hydroxyphenyl)-4-(4-hydroxyphenyl)benzene (a
compound corresponding to the formula (15)).
Examples 13 to 25, and Comparative Examples 4 and 5
(A) to (E) components in blend amounts indicated in Table 3, 120
parts by mass of ethyl lactate as a solvent, and 2 parts by mass of
a 50% methanol solution of ureapropyltriethoxysilane as a coupling
agent were blended. The obtained blend was subjected to a pressure
filtration using a Teflon.RTM. filter of 3 .mu.m in pore to thereby
prepare photosensitive resin compositions of Examples 13 to 25 and
Comparative Examples 4 and 5.
<Evaluation of the Photosensitive Resin Compositions>
The photosensitive resin compositions of Examples 13 to 25 and
Comparative Examples 4 and 5 were evaluated for the following. The
results are shown in Table 3.
(Remaining film ratio, sensitivity, resolution, curing shrinkage
percentage, elongation at break after curing, elastic modulus after
curing, elongation at break after being left at a high temperature,
elastic modulus after being left at a high temperature, elongation
at break after a thermal shock test, elastic modulus after a
thermal shock test, white turbidity of the resin, haze)
These items were evaluated by the same means as described
above.
(Residue)
For the square hole patterns of 10 .mu.m.times.10 .mu.m among the
above-mentioned square hole patterns of from 1 .mu.m.times.1 .mu.m
to 100 .mu.m.times.100 .mu.m, the presence/absence of the residue
at openings was observed using SEM. The case where the residue was
less than 0.5 .mu.m from the end surface of the opening was taken
as A; the case where being 0.5 .mu.m or more and less than 1.0
.mu.m was taken as B; and the case where being 1.0 .mu.m or more
was taken as C.
TABLE-US-00003 TABLE 3 Comparative Com- Example Example ponent
Material 13 14 15 16 17 18 19 20 21 22 23 24 25 4 5 (A) A1 80 80 80
80 80 -- 80 80 80 -- 80 80 -- 80 -- A2 -- -- -- -- -- -- -- -- --
80 -- -- 80 -- -- A3 -- -- -- -- -- 80 -- -- -- -- -- -- -- -- 80
(B) B1 20 20 20 20 20 20 -- 20 20 20 20 20 20 20 20 B2 -- -- -- --
-- -- 20 -- -- -- -- -- -- -- -- (C) C1 5 5 5 5 5 5 5 -- 5 5 5 5 5
5 5 C2 -- -- -- -- -- -- -- 5 -- -- -- -- -- -- -- (D) D1 15 15 15
15 15 15 15 15 -- 15 15 -- -- -- -- D10 -- -- -- -- -- -- -- -- 15
-- -- 15 15 -- -- (E) E1 2.5 5 7.5 -- -- 5 5 5 5 -- -- -- -- 2.5 5
E2 -- -- -- 5 -- -- -- -- -- 5 -- -- -- -- -- E3 -- -- -- -- 5 --
-- -- -- -- -- -- -- -- -- Remaining Film Ratio [%] 96 96 94 95 95
93 90 92 97 74 97 98 80 99 96 Sensitivity [mJ/cm.sup.2] 460 420 380
440 460 480 520 580 520 260 500 600 340 no no opening opening made
made Resolution After Development 2 2 2 2 2 2 3 3 2 2 3 5 5 -- --
[.mu.m] After Curing 2 2 2 2 2 2 3 3 2 2 3 5 5 -- -- Curing
Shrinkage 10 10 10 10 10 12 10 12 10 10 10 10 10 10 10 Percentage
[%] Elon- After Curing 55 55 55 55 55 18 26 13 42 24 55 38 18 5 4
gation at After Being Left at a 40 39 40 39 39 15 18 8 33 16 40 30
13 4 3 Break High Temperature [%] After Thermal Shock 41 41 40 40
39 15 19 10 34 17 41 29 14 3 3 Elastic Test After Curing 2.5 2.5
2.5 2.5 2.5 2.3 2.6 2.7 2.2 2.5 2.5 2.2 2.3 3.6 3.2 Modulus After
Being Left at a 2.6 2.6 2.6 2.6 2.6 2.4 2.7 2.8 2.3 2.6 2.6 2.3 2.4
3.7 3.3 [GPs] High Temperature After Thermal 2.5 2.5 2.5 2.5 2.5
2.3 2.6 2.7 2.2 2.5 2.5 2.2 2.3 3.7 3.2 Shock Test White Turbidity
A A A A A A A A A A A A A A A Haze [%] 0.3 0.3 0.4 0.3 0.3 0.5 0.6
0.5 0.6 0.5 0.3 0.6 0.7 0.2 0.4 Residue A A A A A A A A A A B C C
-- --
As is clear from Table 3, the photosensitive resin compositions of
Examples 13 to 25 were good in the sensitivity, could sufficiently
suppress white turbidity, were excellent in the mechanical
properties (elongation at break and elastic modulus) of the formed
patterned cured films, and were low in the changing rates of the
mechanical properties after being left at a high temperature and
after a thermal shock test. Particularly it is clear that Examples
13 to 22, in which the (C) component contained a thermal
crosslinking agent having an alkoxymethyl group and used an (E)
component had the excellent dissolution contrast between exposed
portions and unexposed portions. By contrast, in Comparative
Examples 4 and 5, in which no (D) component was used, the
sensitivity decreased and the square hole patterns of 100
.mu.m.times.100 .mu.m could not be formed.
REFERENCE SIGNS LIST
1 . . . SEMICONDUCTOR SUBSTRATE, 2 . . . PROTECTING FILM, 3 . . .
FIRST CONDUCTOR LAYER, 4 . . . INTERLAYER INSULATING LAYER, 5 . . .
PHOTOSENSITIVE RESIN LAYER, 6A, 6B, 6C . . . WINDOW PART, 7 . . .
SECOND CONDUCTOR LAYER, 8 . . . SURFACE PROTECTING LAYER, 11 . . .
INTERLAYER INSULATING LAYER, 12 . . . WIRING LAYER, 13 . . .
INSULATING LAYER, 14 . . . SURFACE PROTECTING LAYER, 15 . . . PAD
PART, REWIRING LAYER, 17 . . . CONDUCTIVE BALL, 18 . . . CORE,
COVER COAT LAYER, 20 . . . BARRIER METAL, 21 . . . COLLAR, 22 . . .
UNDERFILL, 23 . . . SILICON SUBSTRATE, 24 . . . CONNECTION PART,
100, 200, 300, 400 . . . STRUCTURAL BODY, and 500, 600, 700 . . .
SEMICONDUCTOR ELEMENT
* * * * *